Works well, but.. - Stern Defense SD BU9 NiB ECHO 9mm Bolt Carrier for AR-15 Glock-Pattern Upper Receiver

I'm not able to make this work with Echo Sport, yet. I *think* I have an H2 buffer and don't think the Strike flat-wound springs are as stout as Tubb flat-wounds. Or maybe you need the regular Echo. That said, the carrier worked flawlessly in conjunction with a Matador Mag-X adapter. Not saying it won't, just I think I need to tweak parts to get it going.