Harken 40mm Carbo Air Double Swivel Block

The Harken 40mm Carbo Air Double Swivel Block is a lightweight, high-performance rigging block engineered for applications demanding low-friction load transfer and compact design. This marine-grade block combines advanced polymer construction with dual swivel attachment points, delivering reliable mechanical advantage in confined spaces where weight and footprint matter. The 40mm sheave diameter accommodates line up to 3/8 inch, making it suitable for demanding rigging scenarios including marine recovery, watercraft rigging systems, and heavy-load repositioning applications.

Core specifications define this block's practical capability: the 40mm sheave diameter with maximum 3/8-inch line diameter rating ensures compatibility with standard marine cordage while the Carbo Air composite construction delivers strength-to-weight efficiency superior to traditional metal blocks. At 0.2 lbs, this double swivel block significantly reduces system weight compared to conventional steel alternatives, critical for overhead rigging, davit systems, and manual hauling operations where cumulative gear weight affects handler fatigue and system response. The dual swivel design allows 360-degree rotation at both attachment points, preventing line twist and reducing wear on cordage during dynamic load cycles.

This block serves professional riggers, marine operators, water sports enthusiasts, and recovery specialists who require compact, corrosion-resistant hardware for challenging environments. The Carbo Air material resists saltwater degradation and UV exposure better than traditional metal blocks, extending service life in coastal and tropical applications. The compact 3 x 1 x 5-inch profile allows installation in tight spaces—deck cleats, boom attachments, and limited-overhead configurations—where larger blocks cannot fit. As part of Harken's proven block lineup, this model delivers the reliability demanded in maritime, rescue, and professional rigging work without premium pricing.