Drop MajorSurplusNSurvival.com a email on product inquiry. They can tell you for sure. They don't have it shown online,but they have carried the harness and buttpack in recent catalogs. Much of the European gear is compatable with our system. they also sell issue shoulder pad inserts for comfort. I imagine the buttpack is secured with the sliding keepers, those big safety pin type attachment points on the canteen cover.<br><br>