Description of Milwaukee 12 Inch Extensions Selfeed (Model 48-28-4006)
It is easy to use. It is highly durable. Made in China. Extension increases your drilling reach 12 inches. For Selfeed bits, auger bits and hole saws. Fits 3-jawed chucks (1/2-inch drill capacity and larger) and 7/16-inch quick change chucks. Also fits 7/16 inch Quick Change chucks.
I love these extensions, I bought 2 because they have clasps on the end of the drill motor so they can be stacked. The mount is important because with some good locktite on the set screw and safety tape around the set screw they will not loosen or come apart. If they break up, you've just lost a $30 drill. The packaging was also good and was sent with UPS, so that you could always track where the package was. I'm glad they didn't send via Smartpost.
I bought this extension to use with a large self drill. When I received it I was impressed by the weight and quality. However, the description includes what the extension fits into, but says nothing about what the extension fits into. As it turned out, the large drill I had to use with the extension didn't fit the extension. I'm stuck with a short bit and a useless extension. Three stars for quality but no more for uselessness due to poor description.