I have a Hitachi cordless drill.
[!]http://ecx.images-amazon.com/images/I/41ZTVY129WL._SL500_AA300_.jpgHitachi cordless drill:
You can turn the gray numbered part to switch between, hammer drill, drill and screwdriver mode. The screwdriver mode is numbered up to 22. Can someone explain what the different numbers mean? I haven't really noticed a difference between them.