63mm (2-1/2") Low Profile Dustport directly accepts a standard 2 ¼" Shop-Vac ® hose end in the dustport opening. You can also attach a standard 63mm (2-1/2") dust collection hose around the outside of the dustport opening with a single hose clamp. The fitting itself attaches to the back of most router fences with two standard wood screws. The low profile makes this fitting an excellent add-on to any drill press fence system.