【Premium Quality】The pool winter plug is made of sturdy rubber and stainless steel wing nuts. The material has no pungent odor. The conical shape provides a good seal. 【Effective Protection】The rubber pool winter plugs are easy to install. They prevent water from flowing into the pipe in winter and thus reliably protect the nozzles and drainage openings from frost damage. 【Stainless Steel Wing Nut】Compared to plastic nuts, the stainless steel wing nut can withstand a better load when tightened and is not easy to break. It can also be used to firmly screw the plug onto the end of the pipe to make it waterproof. 【Wide Applications】The pool plug has a diameter of 38 mm. It fits all standard pool inlet nozzles and is also suitable for pressure testing or pool hose maintenance.