Clamping a regulator first stage body in a vise may cause irreparable damage. The First-Stage Body Holding Tool has both a 3/8" and a 7/16" male threaded end to allow threading into the LP or HP Ports of the regulator body and a square center section for a secure vise mount. Once screwed into the body, the center bar on the tool slides so it can be moved to provide maximum access to work on the body.