Ronstan Series 55 Ratchet Mount Orbit Block - Cheek - Clockwise Rotation

The Ronstan Series 55 Ratchet Mount Orbit Block in cheek configuration with clockwise rotation is a premium marine tackle block engineered for serious sailors and cruising boaters who demand reliability under load. This compact, high-performance block mounts directly to your boat's rail or spar and delivers exceptional mechanical advantage for sheet control, halyard tensioning, and mainsheet systems. Built by Ronstan—a trusted name in marine hardware for decades—this ratchet block combines efficiency with durability, making it ideal for both racing crews and long-distance cruisers navigating variable wind conditions.

This ratchet block delivers up to 20:1 holding power through its innovative automatic and manual ratcheting design, which allows you to haul sheets efficiently and then lock them in place with minimal effort. The smooth easing mechanism prevents sudden sheet slippage while the high-performance cleating geometry ensures secure grip even under extreme load or rough seas. Weighing just 0.2 pounds and measuring 3 x 1 x 6 inches, the compact orbit design minimizes windage and weight aloft—critical factors for performance sailing. The clockwise rotation configuration ensures intuitive operation for port or starboard rail mounting, while the marine-grade construction withstands salt spray, UV exposure, and the constant flex cycles of active sailing.

This block suits monohull and multihull sailors operating anywhere from coastal day-sailing to ocean cruising, as well as professional charter and racing operations needing bulletproof sheet management. The cheek-mounted configuration integrates seamlessly with standard 3/8-inch to 1/2-inch rope and works with existing Ronstan track systems or universal marine rail bases. Installation is straightforward for anyone familiar with basic sailboat hardware; simply secure the mount base to your preferred location, ensure clockwise rotation aligns with your sheet routing, and you're ready to sail. Compatibility with both synthetic and natural fiber sheets makes this block versatile across traditional and modern rigs alike.