Single Block with Aluminum Cheeks. Universal Head design may be locked in place or allowed to swivel. Delrin sheave maintains strength and low-friction. For boats to 34'. Sheave Dia. 2 3/8", Thickness 1 3/32", W 2 1/2", L 5 1/32", SWL 2250 lbs., Weight 7.4oz, Max Line size 1/2".