Hello.
This is one GST-64 Type Tank Position Light (Marker).
Two version color filter: Normal: Green filter front, Red filter the rear and the turret, 2.nd version: All white filter.
The combat vehicle (Russian) is the leader for two normal and two infra-red headlights, right from your set, an infrared command tower (mounted filter) is a normal light-reflector headlamps seed OU-3 type (the target of research), and especially from those in the tank is much more powerful, collimated infrared beam guns.
The infrared beam is generally painted black (very dark bluish purple).
The conventional headlamps (fighting vehicles and rolling stock, freight cars) is necessarily a camouflage, it is difficult to detect the vehicle's side and from above at night.