The Bosch GBH18 V-20K21 18 V 3/4 In. SDS-plus® Rotary Hammer kit features a light, portable rotary hammer with an exceptional impact-to-weight ratio – to deliver performance and efficiency. The GBH18 V-20 hammer – powered by an 18 V 4.0 Ah FatPack battery – drilled up to 100 1/4 In. diameter holes 1-1/2 In. deep into concrete. With 1.3 Ft.-Lbs. of impact energy and a no-load BPM rating of 0-5,850, it'll work as hard as the user.