Snap-on's Torque Adaptor, No. SRD35, is a specialty tool for use with the Ford 6.0L Power Stroke diesel engine-equipped vehicles (including 2003-'07 Ford F-Series Trucks and Excursions and ambulance, law enforcement and shuttle bus conversions). With use of 3/4"-drive ratchet, the torque wrench transmits high torque necessary to loosen and tighten head bolts; eliminates the need to remove the truck/van cab from the chassis to access the rear head bolts; and eliminates the need to remove the evaporator housing.