4 ft x 4 ft square pool pillow made from density thick and cold resistant material. Sturdy and durable to resist severe winter conditions. Protect the pool in winter. The pillow helps spread the ice and reduces pressure on the pool walls. Inflate to 70 percent to allow room for ice expansion and prevent damage to the pool. Water protection. This pool air pillow separates the pool cover from the water surface, keeping the water from freezing on the cover and preventing water from collecting on of the pool cover. Easy to use. Inflate with a common household electric air pump, tie the four ropes to the edge holes, and fix it in the center of the pool. Simple and fast, typically ready in about ten minutes. Compatibility and setup. Designed for above ground pools; 4 ft x 4 ft size, built with density thick material for winter performance. Use scenarios Winterizing an above ground pool in cold climates: place the pillow in the center to spread ice and reduce stress on the walls. Using a pool cover in winter: the pillow keeps water from freezing on the cover and helps prevent water on of the cover. Quick seasonal setup: fast inflation and central placement in about ten minutes for rapid winter readiness.