Thanks, I was wondering because there's no mws markings on the packaging for the carbine version, but from everything I've seen online and just looking at the barrel nut it looks identical between all versions(carbine, mws and block1). Better safe then sorry though. One more thing I noticed looking at the above pic is that one could probably take the ris rails off an mws and put it onto the carbine version without unscrewing anything. Too bad they're not sold separately.