Armtrode...sounds like its for welding Armour Plate. There was a few with ARM in the title, such as Armex and Armoid.
They are stainless, probably 308LMo which is another grade that can be used for dissimilar st st to ms, ms to ms and st st to st st.
Al, I've only ever used it for welding runners onto (very large) 304L valve gates, but I seem to remember reading somewhere that 307 can also be used for welding armour plate, could this also be the case?