Exit Blocks minimise friction in lines passing through the deck or exiting masts and booms. The RF45711HL exit block utilises our Series 40 HHL stainless steel ball bearing sheave, specifically designed for any application where high dynamic or static loads are expected. The Grade 2205 stainless sheave and hub contain captive grade 304 stainless steel ball bearings, all housed within a sleek, anodised aluminium housing. 40mm Stainless Steel Sheave, Anodised Aluminium Housing, Requires 2x 6mm (1/4") Fasteners 83mm Fastener Hole Spacing Materials: Sheave and Bearing Race: Grade 2205 Stainless Steel. Ball Bearings: Grade 304 Stainless Steel. Housing: Anodised Aluminium