I used this tool to drill 2 in. holes in joists for electrical cables using a 14.4 V cordless drill. I had read the reviews here prior to purchasing, so I was deliberately trying ease the saw through to avoid damaging it. Nevertheless, the gears began jamming on the 15th hole or so. I nursed it a bit further, and on the 21st hole, the gears would no longer engage the chuck. On those holes that were successfully made, the measured runout was about 1/16 in. Based on my experience and the other reviews, it seems relatively clear that this tool is probably suitable for very small holes only, if it’s expected to have a relatively long life. Otherwise, it should be used as a “consumable” or disposable tool where there’s really no other option. It’s definitely not a substitute for a stand-alone right angle drill.

With regard to dimensions, the chuck is the widest part, 1.5in. The shaft is only about 1-3/32in. at its widest spot. The 6in. length is measured from the hex end to top of the 90 degree angled portion of the body. The 4 in. length is measured from the tip of the chuck to the back end of the 90 degree angled portion of the body.

I've owned one of these for a few years now and I really love it. No downside to it really except sometimes when you use it you wish you had a third hand.