https://www.africahunting.com/media/trijicon-rm06-rmr-sight.73790/
Trijicon RM06 RMR Sight | AfricaHunting.com
Opposite side from above, note the screw that is used to attach the sight to the rifle.
rmr sighttrijicon
https://redpointvision.com/gideon_optics_omega_green_red_circle_dot_sight_rmr_footprint_optics_for_hunting.htm
Gideon Optics Omega Green/red Circle Dot Sight Rmr Footprint Optics For Hunting
red circle
https://www.targetsportsusa.com/trijicon-rmr-type-20-reflex-red-dot-sight-adjustable-led-rm07-c-700679-p-108464.aspx
Trijicon RMR Type 2 Reflex Red Dot Sight Adjustable LED 6.5 MOA
Trijicon RMR Type 2 Reflex Red Dot Sight Adjustable LED at Target Sports USA with free shipping. (RM07-C-700679)
red dot sight
https://www.olight.com/store/osight-xr-enclosed-red-dot-sight-rmr
Osight XR Enclosed Red Dot Sight RMR Footprint Multi Reticle Optic - Olight
10% Off! Olight Osight XR: A rugged multi-reticle enclosed optic with RMR footprint, 2/6+32 MOA reticles, and magnetic charging. Precision performance. Shop...
red dot sight
https://impulse101.jp/en/mount-rails/3599-dci-guns-rmr-dot-sight-mount-v20-for-tokyo-marui-g18c-electric-handgun-aep.html
DCI GUNS - RMR Dot Sight Mount V2.0 for Tokyo Marui G18C Electric Handgun AEP
DCI GUNS - RMR Dot Sight Mount V2.0 for Tokyo Marui G18C Electric Handgun AEP is available on Impulse101.jp
https://redpointvision.com/new_enclosed_red_dot_optic_sight_shake_awake_solar_power_multi_reticle_rmr.htm
New Enclosed Red Dot Optic Sight Shake Awake Solar Power Multi-reticle Rmr