Compatibility: The inner diameter of these winter caps is 3.81 cm/1.5 inches. They fit most residential pools and are essential for protecting pool components from freezing and contamination during the off-season. HEAVY DUTY WINTER PROTECTION: Our pool cover protects your skimmer and pool jets from ice damage. They effectively block water infiltration, preventing cracks and other damage caused by freezing temperatures. DURABLE CONSTRUCTION: Made with high-quality plastic material, these winter caps are designed to withstand harsh winter conditions and deliver reliable performance year after year. They are essential for maintaining the life of your pool's filtration system. EASY TO INSTALL AND REMOVE: Installing these pipe caps is simple. Simply insert them into your skimmer or check valve to create a watertight seal that lasts all winter. Disassembly is just as simple, making it easy to change seasons. Essential Pool Maintenance Accessories: By incorporating these pool closing plugs