converted means it has had enough parts replaced by american made parts to become 922r compliant. this means its legal to use with higher count magazines than the standard 2 or 3 rounders.
usually but not always the really poor trigger linkages are removed and the trigger group moved forward and a pistol grip installed. fire controls replaced bolt bolt carrier gas piston etc replaced. conversion usually makes the terrible stock saiga run a LOT better.
i just got a converted one and damn is it fun. had it out shooting skeet with a vortex red dot on top this morning. mine needed about a 75 shell breakin before it started cycling. even the converted ones are pretty rough. mine is a cai and its pretty decent all tapco internals. all saigas are izhmash as thats where they are made. whether cai converted it or not i dunno but they probably did. izhmash does not convert them in the states they convert them in russia for legal import which is what makes them terrible guns. its up to us here to convert them back to working reliable shotguns
im very very happy with mine.
"Gun control: The theory that a woman found dead in an alley, raped and strangled with her panty hose, is somehow morally superior to a woman explaining to police how her attacker got that fatal bullet wound." — L. Neil Smith