Our 1-1/2" Twin Sheet Lead Block features a stainless steel body and slider for incredible strength and great looks. The 3-1/2" Aluminum sheave runs on our Nomex(tm)/ Teflon(tm) bearing for strength and low friction . The Stainless Steel screw pin securely locks the car in place. For most boats to 60'(18.3m). Max line (2) 7/8" (22mm), Length 6-3/4" (171mm), Width 1-15/16"(49mm), Height 6-7/32" (166mm), Bearing Height 3-13/32"(87mm), SWL 10,000 lbs, (4545kg), Weight 5lbs 4oz. (2.83kg). Use on Schaefer T Track.