Buy them if no good sell them. Some mags work in some guns others won't. I have Tripp, metalform, checkmate 9rd and some of the cheap 10rd brownells ones all work in my STI. The Tripp seem to feel the best then the checkmate metalform and the brownells In That order. But all function no feed problems at all loading the 10 can be hard and the odd time I drop a Tripp mag sometimes the next round has edged forward a bit but that's rare I tend to count my shots and drop after 9