The buckles are solid and hold firm even when my partner really struggles against them. I love that the under-mattress straps keep everything hidden and tidy, so the bed looks normal when we're done. Positioning drills went from a hassle to a breeze.
The under-mattress wrap keeps everything taught even when she really tests it, and the black straps blend right in with our bed frame. Setup took maybe two minutes per corner and now positioning practice actually sticks instead of becoming a wrestling match.
Wrapped these around the mattress in about five minutes and the straps hold tight enough that my partner can barely shift an inch. The under-mattress design keeps everything hidden and tidy during the day, which is a bonus. Exactly what I needed for teaching proper positioning.