These screwdrivers work by pushing the handle downward and causing a crank drive inside the ratchet shaft to spin the blade. When the handle is released, the blade extends to its original position. By repeatedly pushing the handle you can set loose screws quickly with a very simple operation. When not in use the interchangeable bits can be stored inside of the handle. The gear blade can be set to rotate in either direction by changing the ratchet gear allowing you to remove screws as well as insert them.