Arrow rods are amongst the best in the world. The standard connecting rods on the Rover K series are not the strongest, or lightest, so this is a great place to upgrade. HIGHLY Recommended if turbo charging your engine. Big End Diameter:51.680 G/Pin Diameter:18.000 Between Centres:133.100 Big End Width:22.500 Small End Width:15.050 Bolt Size:5/16 UNF Quantity in Set:4 highest quality double air re-melt steel fully machined uniform machine peening balanced end to end within a gram 100% magnaflux tested laser etched fitted with ARP fasteners supplied boxed into sets with ARP moly and full fitting instructions