Wow, this is the only one of these you'll ever find. Very rare, very early Millers Falls electric hammer. Not a hammer drill, just hammer. Pretty much just an electric solenoid driving a chisel bit. I'm not really sure how the electrics works, but if you plug the round caged thing [maybe transformer?] in and plug the drill into that it works as it should. There is nothing like it to compare it to, or gain information on the internet. If you're a collector of antique Millers Falls tools, this is for you.