Small machinist jack, made from 3/4″ 1018 steel. Shortest height is 1-5/8″, tallest is 2-5/8″. 1″ of screw travel to cover the entire range when used with a 1-2-3 block as a riser. Threaded 3/8-24 UNF to a close fit for minimal play/backlash. 1/2″ counterbore on the bottom to a depth of 3/4″, leaving 3/8″ of thread. It would have been a nightmare to tap the entire depth of the base. I may decide to make a custom 1″ riser with a register to fit into the bottom.