The 10IN1 Hex Key Driver is one of four tools that have the same handle. The others contain metric hex bits, Torx bits, or a combination of square, Phillips, and slotted bits.
Bits must be pushed out of the handle. When a bit is removed the last one used goes into its place.
The tool includes seven bits; six can be stored in the handle.
The end of the handle functions as a 1/4-inch nut driver.

When a tradesman owns multiples of the same tool it means one of two things: He really likes that type of tool or he hates it and keeps buying new ones in the hope that he’ll find one he can stand to use. The latter describes my relationship with most hex keys; I own four or five folding sets, a couple of indexes, and a box of loose keys—and don’t particularly like any of them. But I recently purchased a set of Milwaukee hex keys that has made it far more pleasant to work with hex screws.

The 10IN1 Hex Key Driver came out last year and is the hex key equivalent of a multi bit screwdriver. It includes seven bits, one in the tool and six in the handle. Bits are hard to lose because you must push an old one in to get a new one out of the handle. They can be used by hand in the handle or placed in the chuck of a cordless drill or driver.

Most of the time I use the tool by hand; the handle allows me to twist with plenty of force and the 3 1/2-inch bit reaches places that are hard to access with a set that folds. Best of all, the tool is symmetrical so if you can get the bit into the hex screw you can twist it all the way in or out—there’s no need to remove and reinsert the tip to gain clearance.

The handle contains two features I don’t use but an electrician might, a wire stripper (up to 10-gauge) and a loop maker (a hole through the shaft that can be used to bend wire).

I like the 10IN1 Hex Key Driver; it's my tool of choice for driving hex screws. But as with any tool, there are things about it that could be better. It would be nice to have more than seven bits, though I realize the number was limited by the diameter of the handle. The bits in an index or folding set are automatically organized by size. That doesn’t happen with this tool because when a bit is removed from the handle the last bit used goes into its place. The bits in this kit will fit a lot of things but the smallest one (7/64) may be too large for some items (like the set screws in my countersink bits and some of the high-end bathroom hardware I tried to use it on.

The 10IN1 Driver is available in multiple configurations; I have the SAE Hex Key Driver. Other versions include:

10IN1 Torx Key Driver
10IN1 Metric Hex Key Driver
10IN1 Square Drive Multi Bit Driver (includes square, slotted, and Phillips)

Even if you never (or almost never) use the tool by hand it’s a convenient way to keep a selection of bits on hand to chuck into a drill or hex driver. The 10IN1Drivers are made in Taiwan and retail for about $15.