Ronstan Series 40 Ball Bearing Orbit Block™, Fiddle with Cleat and Dyneema® Link Head RF45521Lightweight Fiddle block with adjustable cleat FEATURES Ultra Lightweight. Low friction 2 stage Orbital ball bearing system. Highest working load in its class. Low profile and compact. High performance cleating Composite C Cleat and fairlead. Convert to a becket version by adding a Dyneema link. Specifications Product Specifications Type of Block Fiddle Sheave diameter (mm) 40mm B. L. (kg) 700 M. W. L. (kg) 325* Max. Rope diameter (mm) 9 Weight (g)