Cam-Lock or U-Lock allows shackle to be fixed or to swivel.
Harken Carbo Air Blocks
Low-friction Carbo Air blocks are lightweight, strong, reliable—and affordable. Companions to our popular Harken Big Boat blocks, these small, compact blocks have very high working loads for safe, easy trimming. Lightweight nylon resin sideplates replace stainless steel straps found in Classic blocks. Densely packed glass fibers reinforce resin for strength.
Shackle blocks lock in two directions or swivel to keep line from twisting
Low-friction efficiency for fast trim and release
Free-running ball bearings roll on curved races, efficiently dispersing load for a higher strength block.