I have to return this item to Revain because I didn't read the description carefully enough. This is not a standard quick change drill bit extension. This is a large diameter, commercial/industrial size extension that will not fit most home use drill presses and is not the same size as the drill bits and extensions that you would typically find at hardware stores. If you need a commercial/industrial size extension, this will likely work well for you. It looks like you can mix concrete (or drill a 2 foot hole) with this thing if you have a drill that will do the same. I really can't rate it positive or negative as I can't use it. Be careful, this is the extension you really need.