Harken's 40 mm Zircon Triple Block - Becket (Part No. 1212) has a maximum working load of 345 kg (750 lb) and can accommodate lines up to 8 mm (5/16 in) in diameter. Its 40 mm (1 9/16 in) sheave is fitted with industrial ceramic ball bearings and caged races to ensure efficient and smooth operation. Zircon blocks are designed to help trimmers quickly adjust sail shapes to changing conditions, making them a valuable addition to any small boat's rigging. These high-performing blocks are available in various sizes and configurations, including single and double blocks, with or without beckets.