Klein Tools 3/8-Inch Nut Driver, 6-Inch Hollow Shaft

Yes. The S126 is a 3/8-inch nut driver built on a 6-inch hollow shaft, so it slides down over long bolts, threaded studs and standoffs instead of stopping at the end of the thread. That is what makes it useful on stacked circuit boards, panel standoffs and long machine bolts where a standard solid-shaft driver bottoms out. Overall length is 9.625 inches (24.5 cm).

No. The S126 is not insulated and will not protect against electrical shock. Klein is explicit about that in the tool's own warnings. If you are working on energized equipment you need a 1000V insulated nut driver instead, not this one. Approved eye protection is called for either way.

Same 3/8-inch tool in two shaft types. The S126 is the standard hollow shaft. The S126M is the magnetic version, which holds the nut on the tip so you can start it one-handed in a panel or box. Both share the 6-inch shaft and 9.625-inch overall length, so reach is identical. Pick the magnetic one for overhead and blind starts; pick the standard one when you are running the driver all the way down a long stud, where the magnet buys you nothing.

The shaft measures 6 inches from the handle, with 9.625 inches overall, so you can get down into deep recesses, junction box knockouts and equipment cabinets that a stubby or 3-inch driver cannot touch. Because the shaft is hollow, depth is not limited by protruding thread either.

No. The S126 is a hand tool with a fixed one-piece handle, not a 1/4-inch hex bit or a socket, so there is nothing to chuck into a drill or impact. For powered work you want a hex-shank magnetic nut setter. Use this one where you need feel and control, such as terminal lugs, standoffs and panel hardware.

By handle color. This one carries a blue Comfordome handle, and Klein color-codes each nut driver size so you can grab the right one out of a pouch without reading the stamp. The handle is smooth and palm-shaped rather than a knurled bar, which matters when you are turning dozens of nuts in a day.

Klein anchors the shaft with internal flanges inside the Comfordome handle, which is what resists the shaft twisting free under load. The shaft is also chrome plated to hold off corrosion in damp panels and service trucks. The tool meets or exceeds the applicable ASME/ANSI specifications, and it is made in the USA.