The torch is important there are a number of different brands and they all use there own brand parts parts. Check the make of the torch and its size
(binzel 15, 24, 25 or tweco 2 ,4 ) there are some 20 makes and you also need to know how the torch is fitted to welder, is it a direct fitting , screw on euro,or tweco style block. Most modern welders are fiied with a euro block and this allows any torch brand with a euro to be attached to the machine.
You will need to replace the liner steel liner for steel wire and teflon liner for aluminium . Take the old liner with also ensure the tips are the correct make and size for your wire. Any FLOW regulator will do ( USUALLY ARGON WITH A SMALL % OF OXYGEN AND OR CARBON DIOXIDE. CARBON DIOXIDE IS ALSO USEDALONE AND MAKES THE WELD VERY HOT. The bottle fittings are different for Argon blends and CO2.) Aregulator with a flow bobbin will pay for its self in she saving on gas usage.(HFC Simpson Welding Products)
ALONE