The Rotary Hammer Drill is used to drill into stone, concrete, and brick. It uses SDS-Plus bits (located in the container next to the drill), which have a carbide tip. This tip is very hard, not sharp, and the hammering of the drill crushes the concrete. The bits are loaded and unoaded by pulling the collar on the tip of the drill back. On the side of the drill there is a knob that can select Hammer+Drill mode, Hammer mode that can rotate freely, Hammer mode without rotation, and Drill Mode. Hammer+Drill is the most commonly used mode, and Hammer only mode would be used with a chisel attachement for breaking rock or scraping.