3 Series Ball Bearing aluminum cheek block with curved base. Fits up to 2" diameter spar section for easy mounting. Delrin(tm) ball bearing sheave ensures low-friction. Stainless steel base provide high safe working load. Sheave Dia. 1-7/16" (37 mm), Max Line 7/16" (11 m), L 3-11/16" (949 mm), W 1" (25 mm), H 3/4" (19 mm), Fasteners (4) #10 RH (5 mm), C/C 3-3/16" (94 mm), SWL 1000 lbs. (450 kg), Weight Stain. 2.2 oz. (62 g), Weight Alum. 2.1 oz. (59 g)