Series 20 Single Loop Top Ball Bearing Block. Precision moulded Acetal sheaves running on stainless steel or Torlon ball bearings provide high performance & low friction. High static and dynamic load capacity. Lightweight. Use for dinghy control lines, dinghy vangs, cunninghams, traveller controls. Materials: Stainless steel ball bearings. UV stabilised Acetal sheave. Marine Grade 316 stainless steel load strap and head fitting. Impact and UV resistant, fibre reinforced Nylon cheeks. Dimensions: Sheave ?: 20 mm Max. Rope?: 4-6 mm Pin ?: 3.0 mm