The bosch gbh 2 28 dv professional rotary hammer with sds plus is the most powerful tool in its class it also has the highest drilling rate and highest chiselling performance in its class it has a 25 longer lifetime than other rotary hammers in its class and offers more efficiency than its competitors the gbh 2 28 gives 27 less vibration that the bosch predecessor model due to active vibration damping there is a rotation stop function for chiselling and a ball grommet for preventing cable