BE SURE YOU GET THE RIGHT ONE FOR YOUR WELDER!
Check your old rheostat on the side of ceramic and see what the ohms say before you buy. There are two different versions, be sure you get the right one, I have both. 

BRAND NEW!  Miller Welder Rheostat, 150 Watt, 14 OHM, 207177 200657 233060  Bobcat 225 225NT 250 250FE 250NT Bobcat 3 phase.

14 OHM