Kreg KMS7714 48-Inch Top Trak
Top Trak mounts to the top-side of a shop-made 3/4" thick fence.  Accepts the head of a standard 1/4" bolt. Features a self aligning L-shpaed mounting foot for easy installation to a shop-made fence.  The top of the trak contains a recess for attaching a 1/2" wide self-adhesive measuring tape.  4' Section.