As shown in the illustration below, the flip stop is fastened to a block with a bolt and wing nut. The block is bolted to a piece of hardboard, which forms a clamp that fits over the miter gauge fence, then locked in position by a plastic knob.
Using the stop is easy. Turn the flip stop up, then square up one end of the workpiece. From here you can quickly flip the stop back down for each cut. This flip stop is sized for a 3" fence, so size yours according to your fence’s height.