DIRECT ACTION FIREFLY® LOW VIS BELT SLEEVEFIREFLY LOW VIS BELT SLEEVE The FIREFLY low vis belt sleeve is designed either as an addition to the HELLCAT plate carrier or as a stand alone item. Made especially as a slick platform for undercover or covert use, it can also be carried as an outer belt sleeve in places, where the risk of snagging must be as low as possible, e. g. in very tight places like busses, trains etc. Stiffened, yet very slim, its designated to be mounted on any 45 mm belt.