Ronstan Series 20 blocks feature precision molded Acetal sheaves running on stainless steel ball bearings, providing high performance and low friction. Perfect for dinghy control lines, dinghy vangs, cunninghams and traveller controls.

Double blocks allow the creation of powerful purchase systems. 2-way head can be fixed at 0 or 90 degrees.

Sheave diameter: 20mm (3/4"). See Technical Specs for more information.