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expiredphoinix | Staff posted Jul 04, 2023 10:44 AM
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expiredphoinix | Staff posted Jul 04, 2023 10:44 AM

Cooler Master MasterBox Q300L Micro-ATX Tower w/ Magnetic Design Dust Filter

+ Free Shipping

$40

$70

42% off
Amazon
17 Comments 16,796 Views
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Deal Details
Amazon has Cooler Master MasterBox Q300L Micro-ATX Tower w/ Magnetic Design Dust Filter (MCB-Q300L-KANN-S00) on sale for $39.99. Shipping is free.

Thanks to Community Member phoinix for finding this deal.

Product Details:
  • I/O panel can be adjusted in 6 different locations and the Case can be positioned: Vertical or horizontal
  • Edge to edge acrylic transparent side panel offers a full view inside
  • Body depth height: Can support normal size ATX power supply
  • Front magnetic design dust filter with open perforated front, top and bottom for high air performance
  • Extra space behind the motherboard tray for hidden cable management
  • Motherboard Support: Micro ATX, Mini ITX, CPU Cooler: 159mm/6.2", GPU 360mm, Radiator Support Front: 120mm/240mm, Rear: 120mm

Editor's Notes

Written by SlickDealio
  • About this deal:
    • This price is $7 lower than the last time this case was a Frontpage Deal.
  • Ratings & Reviews:
    • Rated 4.5 out of 5 stars based on over 14,000 customer reviews.
  • About this store:
  • Refer to the forum thread for additional details and community discussion.

Original Post

Written by phoinix | Staff
Product Info
Community Notes
About the Poster
Deal Details
Product Info
Community Notes
About the Poster
Amazon has Cooler Master MasterBox Q300L Micro-ATX Tower w/ Magnetic Design Dust Filter (MCB-Q300L-KANN-S00) on sale for $39.99. Shipping is free.

Thanks to Community Member phoinix for finding this deal.

Product Details:
  • I/O panel can be adjusted in 6 different locations and the Case can be positioned: Vertical or horizontal
  • Edge to edge acrylic transparent side panel offers a full view inside
  • Body depth height: Can support normal size ATX power supply
  • Front magnetic design dust filter with open perforated front, top and bottom for high air performance
  • Extra space behind the motherboard tray for hidden cable management
  • Motherboard Support: Micro ATX, Mini ITX, CPU Cooler: 159mm/6.2", GPU 360mm, Radiator Support Front: 120mm/240mm, Rear: 120mm

Editor's Notes

Written by SlickDealio
  • About this deal:
    • This price is $7 lower than the last time this case was a Frontpage Deal.
  • Ratings & Reviews:
    • Rated 4.5 out of 5 stars based on over 14,000 customer reviews.
  • About this store:
  • Refer to the forum thread for additional details and community discussion.

Original Post

Written by phoinix | Staff

Community Voting

Deal Score
+26
Good Deal
Visit Amazon

Price Intelligence

Model: Cooler Master MasterBox Q300L Micro-ATX Tower with Magnetic Design Dust Filter, Transparent Acrylic Side Panel, Adjustable I/O & Fully Ventilated Airflow, Black (MCB-Q300L-KANN-S00)

Deal History 

Sale Price
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Sort: Lowest to Highest | Last Updated 9/17/2025, 11:42 PM
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Amazon$39.99

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Top Comments

JWeavis
1029 Posts
120 Reputation
You might think it's a mesh case, but it's not. Take a look at the second pic and see how much obstruction there is in the front & top.
Vop
58 Posts
58 Reputation
I thought this was a pretty neat case when it first came out. I was going to get one until Gamer Jesus tested it. The Fractal Design Focus 2 is a significantly better case at around the same price point.

16 Comments

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Jul 05, 2023 12:44 PM
1,029 Posts
Joined Mar 2007
JWeavisJul 05, 2023 12:44 PM
1,029 Posts

Our community has rated this post as helpful. If you agree, why not thank JWeavis

You might think it's a mesh case, but it's not. Take a look at the second pic and see how much obstruction there is in the front & top.
1
1
Jul 05, 2023 07:07 PM
58 Posts
Joined Oct 2015
VopJul 05, 2023 07:07 PM
58 Posts

Our community has rated this post as helpful. If you agree, why not thank Vop

I thought this was a pretty neat case when it first came out. I was going to get one until Gamer Jesus tested it. The Fractal Design Focus 2 is a significantly better case at around the same price point.
Last edited by Vop July 5, 2023 at 12:12 PM.
1
Jul 05, 2023 07:12 PM
133 Posts
Joined Dec 2007
theruneJul 05, 2023 07:12 PM
133 Posts
I would not recommend this case unless you never need to move it or open it. Unless they changed the design, the rubber feet fall off and the little rubber clips that hold the bottom mesh fall out.
Jul 05, 2023 07:15 PM
2,599 Posts
Joined Jul 2016
Meribela_SJul 05, 2023 07:15 PM
2,599 Posts
Quote from Vop :
I thought this was a pretty neat case when it first came out. I was going to get one until Gamer Jesus tested it. The Fractal Design Focus 2 is a significantly better case at around the same price point.
Focus 2 was great until the glass shattered upon touch. Really uncommon defect but be careful nonetheless.
Expert
This user is an Expert in Computers
Jul 05, 2023 07:27 PM
1,637 Posts
Joined Aug 2013
heavyarms1912
Expert
This user is an Expert in Computers
Jul 05, 2023 07:27 PM
1,637 Posts
Quote from therune :
I would not recommend this case unless you never need to move it or open it. Unless they changed the design, the rubber feet fall off and the little rubber clips that hold the bottom mesh fall out.
The bottom mesh is flimsy can also get folded when those rubber feet fall off
However, I did love the form factor this case for the ATX version, Q500L. I didn't have issues having the intake fans for cpu. GPU temps might suffer a lot if your bottom intake is choked.
Jul 05, 2023 08:19 PM
4,012 Posts
Joined Jul 2012
desynergyJul 05, 2023 08:19 PM
4,012 Posts
This case will inform you how dusty your place is. lol
Jul 06, 2023 05:14 AM
26 Posts
Joined Sep 2019
WittyClub682Jul 06, 2023 05:14 AM
26 Posts
Used this in my build. Works great. The magnetic mesh filters are annoying when moving it around, but they are easily removed and replaced. It was easy to build in. My build was simple, though. If your build is complex, it may not be the right fit. The size is great, too.

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Jul 06, 2023 06:13 AM
2,428 Posts
Joined Oct 2017
essix8Jul 06, 2023 06:13 AM
2,428 Posts
Quote from JWeavis :
You might think it's a mesh case, but it's not. Take a look at the second pic and see how much obstruction there is in the front & top.
Yup, its a hot box unfortunately. People shouldnt buy it unless they are going to mod it, or use lower end parts that wont produce much heat.
1
Jul 06, 2023 11:47 AM
1,024 Posts
Joined Nov 2011
mcl5000Jul 06, 2023 11:47 AM
1,024 Posts
I've been using this case for 3 or 4 years maybe and I've been pretty happy with it. It's small but I've fit both a 120 AIO and a hyper 212. There is plenty of room for fans (I have 4 plus the radiator), but some stuff does have to be strategically placed to avoid the motherboard and other components. It also fits my 3 fan gpu.

I should not have bought this case for my build and I'm probably going to get a larger case soon since it's getting tight in there, but the temps are honestly totally fine for a mid range PC (6650xt/ryzen 5600).

You're totally fine to pull the trigger if you're building a PC under maybe $600 with on board graphics or a low end video card. Anything stronger, I'd go larger just because of space.

People are too paranoid about temps for a cheap mATX case. You aren't buying one of these to put $4000 worth of top of the line components in.

Edit - also note the PSU isn't in a separate compartment so it's in full view all the time. Also, the modular IO is very handy. I was able to put my radiator on the front and move the IO to the top.
Last edited by mcl5000 July 6, 2023 at 04:54 AM.
Pro
Jul 06, 2023 07:54 PM
2,061 Posts
Joined May 2010
artcab
Pro
Jul 06, 2023 07:54 PM
2,061 Posts
Quote from Vop :
I thought this was a pretty neat case when it first came out. I was going to get one until Gamer Jesus tested it. The Fractal Design Focus 2 is a significantly better case at around the same price point.
That was the Q500L, in which Cooler Master reworked this Q300L case to accept an ATX motherboard by changing the PSU placement from the bottom rear to behind the front panel, where it obstructed airflow.

https://www.youtube.com/watch?v=F3n80GxU-Zs
Pro
Jul 06, 2023 07:58 PM
2,061 Posts
Joined May 2010
artcab
Pro
Jul 06, 2023 07:58 PM
2,061 Posts
Quote from mcl5000 :
I've been using this case for 3 or 4 years maybe and I've been pretty happy with it. It's small but I've fit both a 120 AIO and a hyper 212. There is plenty of room for fans (I have 4 plus the radiator), but some stuff does have to be strategically placed to avoid the motherboard and other components. It also fits my 3 fan gpu.

I should not have bought this case for my build and I'm probably going to get a larger case soon since it's getting tight in there, but the temps are honestly totally fine for a mid range PC (6650xt/ryzen 5600).

You're totally fine to pull the trigger if you're building a PC under maybe $600 with on board graphics or a low end video card. Anything stronger, I'd go larger just because of space.

People are too paranoid about temps for a cheap mATX case. You aren't buying one of these to put $4000 worth of top of the line components in.

Edit - also note the PSU isn't in a separate compartment so it's in full view all the time. Also, the modular IO is very handy. I was able to put my radiator on the front and move the IO to the top.
This is a fair assessment of this case IMO. It was pretty popular when introduced, and I believe predated the airflow era, so it was fairly innovative in its time. This case was featured in A LOT of Tech tuber's budget build videos. As long as people know what they're getting, it seems to be a decent enough deal.
Jul 06, 2023 09:05 PM
1,177 Posts
Joined Dec 2006
HexiumVIIJul 06, 2023 09:05 PM
1,177 Posts
This case looks really nice in pics and some videos. But it is one of the flimsiest cases ive ever worked on. Its not bad, but keep in mind its a super cheap case.
Expert
This user is an Expert in Home & Home Improvement
Jul 06, 2023 09:08 PM
4,911 Posts
Joined Oct 2013
wherestheanykey
Expert
This user is an Expert in Home & Home Improvement
Jul 06, 2023 09:08 PM
4,911 Posts
Quote from artcab :
This is a fair assessment of this case IMO. It was pretty popular when introduced, and I believe predated the airflow era, so it was fairly innovative in its time. This case was featured in A LOT of Tech tuber's budget build videos. As long as people know what they're getting, it seems to be a decent enough deal.
You can usually tell when something is "too good to be true" by way of YouTubers latching onto it.
Jul 07, 2023 10:09 AM
565 Posts
Joined Oct 2013
xXSluggXxJul 07, 2023 10:09 AM
565 Posts
I built in this case last year with a i5 12400, msi b660, 3080 founders and corsair 850 watt on air with 7 id-cooling fans including cpu cooler and I've had 0 issues with temps. The mesh screens make dusting easy. As for moving it around I can't attest to that because my pc stays in the same place always. Just fyi the side panel can be oriented however you like. I wanted to go with a smaller than mid size case this time and this fit the bill. Being a slick deal for $30 at the time via gamestop made it even better.

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Jul 11, 2023 12:47 PM
988 Posts
Joined Jun 2005
erthianJul 11, 2023 12:47 PM
988 Posts
Quote from JWeavis :
You might think it's a mesh case, but it's not. Take a look at the second pic and see how much obstruction there is in the front & top.
I'm actually a big cooler master fan but whew this case is shit. Wish I'd gone with something else.

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