That is it but not just suppressor mounts, many excellent MDs are will get you to 16.1" with 13.7", SOLGW has non-mount version of the NOX as does Surefire. Also, with it has a forgivable dwell time and it is the shortest barrel to work well supressed or unsupressed with mid-length gas system, sort of the 11.5 of the carbine world.