The new MIG 135 models can run the same spool gun as the MIG 175 and 250. If you already own a MIG 135 just look for a white switch inside the unit above the drive motor. If your machine has this switch you are good to use the spool gun. Use with 100% Argon Gas when welding Aluminum. For use on machines WITH A METAL Plug on the machine and torch lead. Includes: 1 Spool Gun w/ one 1 LB spool of .035 aluminum wire. Always wear a minimum #10 shade helmet, leather welding gloves and long sleeve shirt and long trousers.