{{Hebiquote
|quotetext=The RO635 is not merely a submachine gun-length calibersized AR-15 carbine, like the [[Mark 18]]; it is an actual, literal submachine gun. Though still considered to be part of the AR-15 family, this model is mechanically different, using a simpler blowback operation instead of the direct impingement gas operation system that defines the rifle-caliber AR-15s. Despite that, the RO635 uses the exact same ergonomics as its more powerful cousins, and is viable as both a training platform for other AR-15 rifles and as a legitimate workhorse submachine gun.
|quoteauthor=Tempest
}}