Size 1 30mm Plain Bearing Pulley Block Single Fixed EyeThe Size 1 Plain Bearing Blocks have a 30mm (1 3/16") sheave. The range is designed with an internal steel frame for added strength and durability. Also available in ball bearing sheave options, the lightweight modern design is available in variations that allow for a multitude of uses on every size craft.The 30mm sheave Size 1 block range is designed with an internal steel frame for added strength and durability. Available in plain and ball-bearing sheave options, the lightweight modern design is available in variations that allow for a multitude of uses on every size craft.Suitable for up to 8mm (5/16") rope. Quick Guide (pdf)