Aviation Specialties Unlimited, Inc. offers everything you need to inspect, service, and repair your NVGs.  We offer an array of Hoffman test equipment NVG test kits, focus systems, purge kits, and toolsets, as well as other specialty items, such as N2- GEN 4 - Compact Nitrogen Generator. In addition to NVG lab equipment, ASU offers NVG Testing and Maintenance repair courses to train your technicians to inspect, service, and repair your NVGs which will minimize downtime and extend the life of your NVG equipment.