Not only are AirBlocks® a quantum leap forward in technology, they are at the same time wonderfully simple and highly suitable for the Caribbean. With high strength-to-weight ratios and free-rolling, high-load roller bearings, these versatile blocks are the workhorses of the Harken® line. Use for sail controls that see lots of action including mainsheet, runner, halyard, and spinnaker systems. AirBlocks® are very easy to clean and service. They have few parts and no loose balls or rollers to misplace. Unlike blocks that are riveted together, three fasteners allow quick disassembly for service.