Walmart offers the Hover Cover Microwave Splatter Guard [walmart.com]
for $9.42. Opt for in-store pickup to avoid the $5.99 shipping charge.
Product Description (provided by Walmart):
As Seen on TV Hover Cover Microwave Splatter Guard is the new microwave splatter guard that uses microwave-safe, polymer-encased magnets that secure to the roof of your microwave, so it is always ready to use. Just pull down to cover and when youre done, lift and let it hover! Best of all its BPA-free, always cool to the touch, and dishwasher safe. Get your As Seen on TV Hover Cover Microwave Splatter Guard and start protecting your microwave from splatter today! As Seen On Tv Hover Cover-microwave Splatter Guard:
Special microwave-safe, polymer-encased magnets Secure It
Protects Against Food Splatter
Fits Virtually All Microwave