Sterling Sleep System Fitted Safety Liner - Shallow Fill (3.25") Twin Size 38x75 Inches - Waterproof & Breathable Mattress Protector for Kids, Toddlers & Elderly Care

8mil vinyl. Suitable for: deep fill waterbeds (8") The fitted safety liner is designed as an extra safeguard against unlikely leakage of your waterbed. It's important to get the placement of the safety liner correct. If you have any questions, see our article below.