I wanted to use my arrow saw to cut carbon fiber tubes, but the stock end stop was too small.  The rest with the stop built in has the same shape as the front rest by the saw, so larger diameter tubes can be cut to a length set by the measuring tape.  For tubes longer than the length of the saw, use the rest without an end stop and a collar clamped on the tube that abuts the rest.  The included collar is used for a tube with .500 ID and 1/32" wall.  The rests need tapped for a ¼-20 clamp screw.