We used those when I worked at NWB in Omaha in the early 70s. Punched many a small hole for an anchor to hang a telephone on a wooden backboard on a block or cement wall. Hammer drills were pretty hard to come by back then for an ordinary install or a repair job. By the way if you use it make sure you turn it every couple of hammer blows or it gets stuck in that position and then you've got a mess