Sta-Rite strainer cover-6 inch. For pump strainer baskets. Outer thread ID is 6 1/2 inches. Biguanide resistant. O-ring sold seperately below, lube with silicone grease (magic lube, Jack's, etc.) Availability: Usually ships the next business day. H351021169$68.00 Availability: Usually ships the next business day. O-ring H351021171$4.00 CNY Hot Tubs - 2037 St. Rte. 34, Lansing, NY 14882 Phone: 607-533-9411 - Email: info@cnytubs.com - Web: www.cnytubs.com CNY Hot Tubs acknowledges all trademarks. Copyright ©2001-2008 CNY Tubs All Rights Reserved.