Ring Alarm Contact Sensor, 2 Pack, 2nd Gen, $29.99, Lowes
These are normally $20 each. The first gen have been clearanced for a while at $15. Just picked 3 two packs up in store, but also available for delivery. Does not indicate on sale, so not sure why the lower price. Also strange that Lowe's calls them access tags. I have purchased multiples and confirmed. In-store and online.