Intended for use in both contaminated environments (CE) and shallow water diving or light salvage conditions requiring voice communications, the EXO-BR-MS is a lightweight alternative to the fully enclosed Mk. 21 system. The EXO-BR-MS is a "band mask" meaning that it uses elastic straps to remain seated on the diver's face, as opposed to the neck dam and locking collar used on the heavier Mk.21 mask. However, since the diver's nose, eyes, and mouth are fully enclosed, the EXO-BR-MS is compatible for use with all wired communication systems and many wireless systems. In addition, because of the mask's light weight, divers may work for extended periods in most conditions without experiencing undue fatigue. The EXO-BR-MS is compatible with both surface supplied and SCUBA air systems. The mask is certified to 28 degrees F. and for a number of compressed air or mixed gasses; 190 feet sea water (fsw) for compressed air, 140 fsw for NITROX, and 300 fsw for helium-oxygen.