Perfect winterizing plug for Above-ground and In-ground pools during winter Protect your swimming pool in winter with these threaded return pipe caps. These covers prevent water from entering the oil return line. This can prevent the freeze water from expanding and contracting, resulting in damage. Plugs are made of high-quality to tolerate extremely cold temperatures without slipping or shrinking Compatible with most , , , and of pool filters The cap measures 1.5inch along the bottom where the threading is. It is a male threaded plug. color:White :plastic Package Contents: 6 x Drain plug Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.