Diesel engine bay and heavy equipment undercarriage bolts are buried 8 to 10 inches deep into the recess — a 3-inch or 6-inch extension gets you there but then you're working with no control, the whole shaft flopping. This 1/2-inch drive 10-inch impact extension gives you the reach you actually need with a magnetic socket holder that keeps the socket locked on from first strike to final torque. Chrome vanadium steel handles the high torque output of an impact gun without bending or walking. The 10-inch length is the go-to for diesel mechanics and heavy equipment techs who work on engine bays and undercarriage fasteners that standard extensions can't reach. Standard in diesel mechanic tool sets across northeast Nebraska and northwest Iowa — the deep-reach extension that doesn't compromise o Stocked at Crofton Lumber and Akron Lumber.