This inflatable winter pool pillow is made from ultra strong and durable, 0.24mm thick, cold-resistant PVC material. It helps protect above ground pool walls and covers from pressure caused by expanding ice, absorbs freezing water as it expands, and reduces the build-up of rain, leaves or snow on your winter cover. With reinforced grommets at four corners and a double fold valve, it's easy to inflate and deflate and stays in place at the center of the pool. Best for protecting your above ground pool during the cold winter months. Features 1. PROTECT YOUR POOL DURING ALL WINTER: Our pool pillow creates surface tension which effectively protects above-ground pool walls and pool covers from pressure caused by expanding ice. This prevents expanding ice along side your pool walls. 2. DESIGNED TO WITHSTAND COLD WINTER: This 4ft Winter Pool Pillow is made from ultra strong and durable, 0.24mm thick, cold-resistant PVC material. 3. GREAT PROTECTION: Air pillow absorbs freezing water as it expands. Relieves above ground pool walls from stress of ice expansion. Helps reduce the build-up of rain, leaves or snow on your winter cover. 4. STAYING IN PLACE: Just slips the included rope through and tie the pool pillow to your pool and the reinforced grommets at four corners around the pillow to keep the pillow in position at the center of the pool. 5. INFLATE & DEFLATE EASIER: We chose double fold valve, which allows inflating and deflating much more faster without lossing of air. Works seamlessly with most blower. Foldable desin, easily roll it up to storage. Specification Material: PVC Color: Blue Size: 120 x 120 cm Weight: 550 g Package Include: 1 Pool Air Pillow