A lot has changed since I began in construction and this here is one of the innovations. When using auger bits to drill holes, or even hole saws, these are invaluable. You can insert any bit with a 7/16 shank into the end and go wild cutting holes. These guys cut holes very fast and when they hit something, they will not pull your arm out of its socket, or break your wrist. The just start impacting and pull right through. The ring adapter make hanging this on your belt easy. Then you also have the old quick lok tol cord that allows you to add a 25' long cord for real work and you have a heck of a tool. Last thing, you can add a 7/16 insert that will allow you to use standard 1/2" drive sockets and you can pull lugs off cars or spin nuts on hex bolts through beams in a flash. Also once you get to the 1/2" square drive, you can steps down to 3/8 sockets or 1/4 bit drivers. These are great for driving your powerlags, headloks, trussloks, ledgerloks, etc. A little heave for construction screws, but unlike cordless, they never run out of battery! Adjustable torque and easy to use forward and reverse.... you do a lot of hole cutting and bolt running you will never miss this guy!