Good call, NSS,
All SD80/90MAC's, 40's, 40-2's, C44-9W's and others take (2001's for tighter curves) 2004's. Geep 20's, SW1200's, Geep 40's , SD60's? and others take 1015's.
In short, most Katos take 2004's or 2001's. a GENERAL rule. Not always applies.
Most Atlas' take 1015's, but that is...