A mount is the connection your optic lives or dies by. One-piece cantilever mounts from Geissele and Aero Precision hold riflescopes at proper eye relief on flat-top ARs, American Defense Mfg. QD levers let optics come off and return to zero, and optic-specific mounts from Kinetic Development and others fit footprints like the ACRO and Trijicon RMR. Buy the mount like it costs what the optic does — it protects exactly that.