4” length reaches past cam and rocker assembly to service head bolts Thin profile sockets will reach through the access hole and past overhead camshaft Additional high torque applications include removal and installation of driveline bolts on most vehicles Forged from Cr-Mo alloy steel for long life All Sunex® impact sockets meet or exceed ASME specifications On Mar-14-17 at 13:49:22 PDT, seller added the following information: Protect Your Product With a Consumer Priority Service Warranty