Ronstan Series 15 Ball Bearing Utility Block - Double, Loop Head

The Ronstan Series 15 Ball Bearing Utility Block – Double, Loop Head is engineered for sailors, riggers, and professionals who demand lightweight, frictionless performance in demanding marine and industrial applications. This double utility block delivers precision mechanical advantage while minimizing weight and resistance, making it an essential component for halyards, sheets, and general rigging systems where smooth operation directly impacts efficiency and safety.

At just 0.05 lbs, the Series 15 is the smallest and lightest ball bearing block available in its class, achieving this distinction through precision-molded acetal sheaves mounted on stainless steel ball bearings. The acetal construction provides durability and corrosion resistance while the ball bearing design virtually eliminates friction, enabling smooth load transfer and reducing the physical effort required during operation. The loop head design integrates seamlessly into existing rigging systems, allowing for rapid attachment and adjustment without additional hardware.

This utility block suits cruising sailors, racing crews, commercial fishing operations, and industrial rigging professionals who prioritize weight savings and low-friction performance. The compact 2 x 1 x 4 inch profile fits tight spaces on masts, booms, and rigging arrays, while the double configuration handles multiple lines or provides a mechanical advantage system. The stainless steel bearings resist saltwater corrosion, making it ideal for marine environments, while the acetal sheave maintains performance across freshwater, industrial, and land-based applications where reliability cannot be compromised.