This California King Size Waterproof Hypoallergenic Premium Mattress protector is made of super soft brushed polyester flannel that allows you to sleep with incredible peace of mind. The flannel layers lock in liquids keeping you dry and comfortable all night long while protecting your mattress at the same time. This waterproof mattress pad is low profile in the fitted style - able to fit mattresses up to 18" deep. Wrinkle resistant and easy to put on, this pad will give you protection all night from possible leaks and damage so that you can drift off into a peaceful and easy slumber.