BioPak 240 Revolution, a self-contained breathing apparatus (SCBA) that provides 4 hrs. of life-saving oxygen, protects workers involved with Hazmat cleanup, search and rescue, homeland security, or military operations. Body-contoured profile fits comfortably under protective gear, without restricting wearer’s movements. To reduce operator fatigue, padded harness positions weight of apparatus on wearer’s hips, instead of shoulders. Includes large breathing chamber, in which 3 springs ensure positive pressure. Vents only used air, thereby reducing overall need for oxygen and demand valves. Disposable cartridges expedite absorbent replacement. Also features refreezable cooling canisters, with twist-off lids that allow replacement in secs., while SCBA remains on wearer. All controls and displays keep user aware of operational status via optical warnings and audible alarms. Overall size is about 23 ins. long, 17 ins. wide, and 7 ins. deep. Shielded Biomarine, Inc., a Div. of Neutronics, Inc., Exton, PAprotects against radio interference. All hoses, housing, face piece, and outside materials consist of flame-rated materials. Face piece enhances wearer’s downward, peripheral vision and communications clarity. Various sizes of nose cups and a choice of seals provide optimum fit.