Don't run the risk of having your outdoor swimming pool not functioning properly. Instead, equip it with the proper maintenance parts like the Pentair 1buttress thread closure replacement kit for pool filters. This buttress thread closure replacement kit is designed to fit the Pentair triton ii pool and spa sand filter models tr100 and tr140. It is easy to install and use. Keep your swimming pool in proper working form with the Pentair black buttress thread closure replacement kit for pool filters.