Low-friction Carbo AirBlocks® are lightweight, strong, reliable—and affordable.These are features all sailors look for when choosing sail controls and a real breakthrough in block design. Companions to Harken’s® popular 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 engineering resin are UV stabilized to provide excellent protection against long-term exposure to salt water and sun. Carbo blocks are perfect for the small-diameter hard lines favored by racers.