For the AN/PVS-14 and civilian PVS-14s. The Rail Mount attaches to a Picatinny rail, best suited in front of your scope/optic and allows you to co-witness for use with the optic's night vision settings.
You shouldn't only have a Rail Mount if you have a PVS-14. But you should have a rail mount to backup your J-Arm and also to take the weight off your head.
These are genuine US issue and not some China repro.
