So just alil info for people like me that didn't know this !!! I purchased my dads old Lincoln welder last year from him after he got his new miller... He had some issues out of the this old thing but it was almost free so why not !!! I never could get it to burn in good ... Why I keep breaking welds !!!! So I've changed wire different boards new leads and so on for the past year.... He ran out if gas with his and I brought my bottle over to his house and immediately his went to **** .... Gas sticker was the same ...75/25.... However the little number in the bottom was the same as his tig rig !!!! Yep 100% argon ...... So hard lesson learned if your just an occasional mig welder like me might be something to look for..