The Solano is compatible with Centuar carbon/Veloce/Mirage compact Ultra-Torque cranks. CNC machined. The 5th arm is slightly offset for crank fixing. The 5th bolt hole has no recess for a bolt head as this bolts straight into back of crank.Key Features:Material : 7075 T6 Aluminium,Outers : 46, 48, 50, 52, 53T,Inners : 34, 36, 38, 39, 42T,PCD : 110 pcd Campagnolo offset arm,Colours : Black,Weight : 74g (48T).