This torque ratchet is set at 25Nm. When torque is loaded higher than 25Nm, the gear slips and no increased torque is transmitted. Cylinder heads and spark plugs are protected by this mechanism. Input Drive Size: 3/8" Drive Shape: Square Type: Tool Set for Torque Controlled Spark Plug Installation Includes: Don't need complete set?Click here to buy items individually 3300C Spark Plug Sockets: 16, 20.8 3751J-25 Torque Ratchet 3763-125 125mm Extension Bar Metal Case: W215xH80xT47mm