The Milwaukee 53 Piece SHOCKWAVE Impact Screwdriver Bits, Magnetic Bit Holders Marker Set is an exclusive set of hardwearing and durable screwdriving accessories along with a long-lasting marker to ensure perfect screw placement Shockwave Impact-resistant accessories are the system solution in the field of impact screws. The innovative system accessories are not only impact-resistant and therefore suitable for use with impact drivers, they also offer the right accessories for all drilling and screwing applications. The flexible SHOCKZONE in the screwdriver bit holder reduces the load on the bit tip and thereby the risk of breakage. The combination of the SHOCKZONE and a special hardening process absorb the impact. The steel alloy developed for Milwaukee is specially designed for use with impact drivers. The Shockwave bits are therefore more stable and at the same time more flexible, ideal for hard screwdriving. The screwdriver bits are ideal for heavy duty impact applications, but also delivers a full system solution for all the users drilling and fastening needs. SHOCK ZONE geometry - Designed to flex, reduces stress at the tip resulting in less tip breakages. The combination of the SHOCK ZONE design and special heat treatment absorbs impacts and allows the bit to flex with spring like action. Precision milled tip provides the best fit with screw head, reducing cam out and stripping, resulting in outstanding lifetime. The Milwaukee INKZALL Fine Point Marker stays sharp, doesnt mushroom or push back under pressure. The marker continues to write after 72 hours of cap off time. Ideal for use on concrete, wood, metal, plywood, OSB, plastic. It can be used on wet, oily, dusty, rusty, with debris surfaces. Quick dry time reduced smearing markings on PVC, metal surfaces. The thin body allows for use in restricted areas with easy open cap for one hand operation.