The compact 29 mm carbo is extremely strong. Use the miniature Carbo as a mainsheet block on small dinghies such as the optimist, or for low friction control blocks on any size boat. Doubles and Triples feature U locks to hold the swivel in front or side position or to let it spin freely. The triples' compact cam arm supports the hi-load purchases of 5:1 or 6:1. The line shedding cheek block features a small mounting footprint and drainholes. The low-profile ti-lite replaces the head post, shackle, and spring with high-tech line. Low friction carbo Airblocks are lightweight, strong, reliable, affordable. Companions to the popular Harken Black Magic line these small compact blocks have very high working loads for safe easy trimming no matter how hard the wind blows. Sideplates of high strength resin are UV stabalized to provide excellent protection against longterm exposure to saltwater and sun. Carbo blocks are perfect for the small diameter lines favored by racers