*Portable bed rails should not be used with infants. Hiccapop bumpers don't “cage in” your child like traditional metal bed rails. Invented at Stanford University based on the principle of “Passive-safety Protection”, the gentle touch of the hiccapop bumper subconsciously triggers your child's natural “Passive-Safety” response, letting them know they are close to danger and should move away. They are the perfect height and ideally sized to allow ample room for your little one to stretch out while sleeping. Hiccapop bumpers pass all federal safety standards for bedrails and are easily installed in seconds underneath a fitted sheet. The bumpers fit twin, full, double, queen and king beds and come with a waterproof, washable nylon cover.