Size 5 54mm Plain Bearing Pulley Block Single Block SwivelThe Size 5 Barton range of blocks has a 54mm 2 1/8" sheave. They are rugged construction, featuring high-grade molded side plates that are through-bolted and riveted for added strength and security. All load-carrying components and interior frame are from marine grade 316 stainless steel and both plain and ball bearing sheaves are available. This sleek and versatile range is engineered for use on larger cruising and racing yachts and is compatible with our ball-bearing mainsheet traveler system.The 54mm sheave Size 4 range is of rugged construction, featuring high-grade molded side plates that are through-bolted and riveted for added strength and security. All load-carrying components and interior frame are from marine grade 316 stainless steel and both plain and ball bearing sheaves are available. This sleek and versatile range is engineered for use on larger cruising and racing yachts and is compatible with our ball bearing mainsheet traveller system.Suitable for up to 12mm 7/16" rope. Quick Guide (pdf)