Secoroc backhammers can be fitted in a suitable tube joint between the drill support and the rotation head. It provides an effective combination of backward hammering and vibrations. To further increase efficiency, simply drill a hole in the choke plug to maintain flushing. If conditions are particularly demanding, two backhammers can be fitted one after the other. The Secoroc backhammers come in just three parts with a plastic casing - the plastic casing functions as a muffler as well as diverting the discharged air. Secoroc, Card No. 303