I purchased this item to drill 7/16" diameter holes in a concrete driveway. I first tried drilling through them with a Milwaukee 12vdc hammer drill. But I was only able to partially drill one hole and with all three batteries charged I decided to buy a Skil rotary hammer. I was able to quickly drill 24 holes and still charge the battery to over 80%. I bought a keyless chuck with an SDS adapter to use this tool as a standard 1/2" drill bit. Would recommend to anyone looking for a good DIY tool.