Detailed product specifications Manufacturer: FCP Engineering Model: FCPRHO14315221 Profile: H beam Spacing: 143.1 mm Large tip diameter: 52 mm Bolt diameter: 21 mm Quantity: 4 pcs., 8 pcs. ARP2000 3/8" screws Material: forged steel 4340 EN24er Maximum engine power: 600 HP (4 cylinders)Maximum revs: 9000RPMOpel / Vauxhall - 2.0 16V (C20XE, C20LET, Z20LET, Z20LEH, Z20LER) Amazing results achieved by our customers without any failure!Opel Corsa C20LET 800+KMTurbo: KKK31 flow 2.5barWeight: 740kg 1/4m. 9.6s! http://www.youtube.com/watch?v=JQnoR6HjoI0