GREAT WORKING CONDITION WITH HELMET MOUNT! The AN/PVS-21 is a Low Profile Night Vision Goggle that utilizes sensor fusion technology to move the image intensifier tubes out of line with the optics creating two very unique benefits. First, it allows the width of the unit to be significantly shorter than most other NVGs. In most cases, this translates to 3-4 less protrusion from the operators face. Low profile is very important in close confines. It better allows the operator to fit into smaller spaces and keeps the unit from snagging on obstacles and gear. The AN/PVS-21s see-through ...