These line snubbers absorb shock on dock lines, booms, dinghies and much more. The patented Progressive Tension Shockles system means that the harder the pull on the Shockle, the stiffer the tension becomes, gradually absorbing any shock load to your boat, cleats, chocks or pad eyes. Use to keep constant tension on your dock lines; take the shock out of a boom preventer; soften the pull on D-rings when towing a tender; tie down your boom without tensioning your running rigging; or as a shock-absorbing tack line for lightweight asymmetric spinnakers. Captive 316 stainless steel carabiners can’t be lost. Sun- and abrasion-resistant nylon webbing cover. All parts rated to at least 2,500lb. MWL.