Foam Perfect for transitioning from crib to big bed; works with any size bed from toddler to king and even as a bed divider for co sleeping Features a non-slip bottom so you can rest assured that your child is safe and sound Our super soft bamboo cover is natural and washable, yet still waterproof so the bumper can last you years to come So easy to install and ultra-light for travel. Size: 52x7x4.5" Our bed bumper conforms with all federal safety regulations including ASTM F2085-12 Safety Specification for Portable Bed Rails - Child may roll over the bumper, or push aside, and it is not intended to prevent falling out of the bed