Ronstan Series 25 Utility Block - Single - Loop Head

The Ronstan Series 25 Utility Block – Single – Loop Head (RF571) is a compact, single-sheave pulley system designed for sailors, boaters, and riggers who demand reliable load management in confined spaces. This utility block is perfect for applications such as mainsheet systems, boom vang tension control, and rigging deck hardware on various vessels, from small cruisers to racing yachts.

Constructed with durability in mind, the Series 25 features a single sheave optimized for smooth rope travel and reduced friction under load. Its lightweight profile and minimal footprint make it ideal for tight cockpit layouts where performance is essential. The loop head attachment point simplifies installation and allows for quick repositioning without the need for tools, making it a practical choice for on-the-water adjustments.

This block is suitable for both cruising sailors looking to upgrade their rigging and performance racers fine-tuning their sail control systems. The loop head design is compatible with soft-shackle attachments or carabiners, providing flexibility in rigging options. Ronstan's engineering ensures consistent performance across varying line tensions and environmental conditions.