BANBALOO - 2-Pack Inflatable Bed Bumper for Children - Child Fall Protection,

It is made of 0.2 mm TPU, this material is much stronger than PVC, so we will avoid punctures or air leaks. To do this, it is enough to blow or use an inflator. Once inflated, the barrier should be placed on the side of the bed and adjusted between the fitted sheet and the mattress.

eBay