DEL-TRON PRODUCTS Magnetic Deck Bridge  Part No.DEL-MDB500 Deltron custom 3 hole magnetic deck bridge with neodymium high pull magnets. A dial indicator with a 3/8" diameter stem housing can be installed in the center hole or left/right holes  and you can install 2 indicators for piston's deck average. Made in the USA. Dial indicator not included. Please e-mail with questions