Fiddle block with v-jam cleat. Works with 02-13 for a 3:1 purchase system. Delrin(tm) sheaves on plain bearings ensure smooth operation. Length 4-7/16"(112mm), Width 2-5/32" (55mm), Thickness 15/32" (12mm), Weight 3 oz, (85g), Safe Working load 900 lbs (410kg)