Night Vision Devices PVS-7 Gen 3 Goggles with HP+ TubeThe Night Vision Devices PVS 7 Gen 3 Goggles with HP+ Tube is the commercial grade housing with the top level commercial grade tube. The water resistant housing is a bit lighter and less robust than the MIL Spec version. Photocathode Response for the HP+ is a minimum of 2500 A lm (micro amperes lumen). The goggle itself is the single tube dual eyepiece type (which is the definition of PVS 7).