1. Compared with percussion drills, electric hammer drills can generate stronger impact force lightly, allowing for effective and precise drilling. Before using the hammer drill, you can use a chisel to make a point of strength, and then combine the hammer drill to meet your processing needs. 2. It is featured in a harder YG8C Carbide tip and carbide steel body. The robust head is ideal for high impact applications. It allows for precise starts in materials such as reinforced concrete. 3. The SDS - PLUS shank is suitable for most rotary hammer drills on the market and meets most of your needs. SDS chisel matches the electric hammer drill to punch hole for concrete, brick and wall, cut and chisel groove. 4. The bit set includes 13pcs drill bits with 5.5 mm, 6 mm, 6.5 mm, 7 mm, 8 mm, 10 mm, 12 mm, 14 mm, 16 mm (approx. 3/16', 1/4', 5/16', 3/8', 1/2', 9/16', 5/8') , 1 Point Chisel, 2 Flat Chisel and 1 U-groove Chisel.