Superlock D1 Rope Clutch Dbl 10-12mm. Lewmar has redefined rope clutch technology with a variable geometry handle and unique grip pattern of dominoes that prevent rope fray. This revolutionary system has been independently tested time and again and has won awards for its innovative framework. Domino Cluster and longer holding pattern holds line under load without fraying the rope. Controlled Release - Pull-back handle, combined with patented clutch and release mechanism, provides controlled release even at full holding load. Handle has a solid link to the domino cluster. Easy installation. Includes decals. Lewmar D1 Rope Clutch Features: High-load applications on boats up to 32 ft. Low load and control line applications on larger boats. Line sizes from 1/4" (6mm) to 7/16" (12mm). Safe Working Load - 1,100 Lbs. Fasteners and position per industry standards. Use 1/4" (M6) panhead fasteners (not included) - Do not tighten beyond 10N.m torque.