The Snap-on Tools 3/8" Offset Extension Wrench, No. FRW10, extends reach of impact and pneumatic wrenches. This reversible, chain-driven extension is metal-encased with rubber end boots to extend the reach of 3/8" ratchets and sockets by a full 10". With zero-degree swing arc, it allows impact and pneumatic wrenches to access fasteners buried in assemblies and the ratchet to swing free and clear. The FRW10 makes it easier than ever to get to the serpentine belt, power steering pump, starter, A/C compressor, sway bar link, under-carpet body-mount bolts and alternator, engine, front-cover and timing belt brackets, the company says.