Durable high quality completely weatherproof patented universal clamp-on mount boat cup holders. The smaller universal clamp fits from 1 1/2 inch outside diameter to as large as 2 inch OD. Once installed, will rotate 360 when pushed around pipe but will not migrate down, unless forced. Smart cup - fits, 20 & 30 oz., larger tumbler cooler cups & a can with or without foam insulator. Stabilized to resist saltwater, UV damage, harsh outdoor elements & abuse, comes with slot for pliers. Will not get brittle, yellow, or break down.