I just made my own centershot guage similar to the Golden Key True Center Guage by taking a wire coat hangar, cutting the straight part that runs along the bottom, and than bending it around a carpenter's square so that it forms an L that I know is square. Than I just found a flat spot on my riser right above where the rest attaches, and measured the distance to the nock point and marked it with a permanent marker on the coat hangar. Than I turned it around and adjusted my rest until the arrow came right in.