The Bosch 1600A024LN GFA12-H FlexiClick Adapter Hammer Drilling Auxiliary Handle. When attached to a Bosch 12V drill driver this allows it to work as a hammer drill. Attaches easily to the tool thanks to Bosch's FlexiClick system and can cope with an impact energy of 0.9 J. Ideal for professional electricians because with the drill driver you can drill into metal but with this attached you can use the same drill to knock through concrete to make installations in walls and under floors. This power tool attachment is sold with a depth stop.This is for the attachment only - no drill is provided.