The Dewalt DT70754 SDS Plus Masonry Drill and Driver Bit Set in a Connectable Case allowing multiple sets to be stacked and locked together The Dewalt DT70754 is a 19 Piece Masonry Drill and Driver Bit Set that comes in a modular, stackable medium tough case. Designed for secure storage of accessories. Clear lid for easy bit identification. Easy bit removal and replacement. Use the locking system to connect the cases together, and securely stack with small, medium, and large Toughcases. Features: TSTAK compatible to hold all your accessory sets in one place Compatible with the TSTAK system via the Large Tough CaseToughcore - tapered central core increases stability and durability, reducing breakage Adds strength and resistance when drilling deep holes with increased side loads Reduces flexing between the flute and shank, preventing bit fracturing Wear Mark - indicates that the holes you drill are the diameter you need. Ideal for accurate mechanical anchor installation 2-Stage Helix -