Certified by NIOSH, MSHA, CEN and MA for mine and tunnel rescue, hazmat cleanup, military and homeland security operations, the BioPak 240 Revolution 4-hour rebreather boasts a 6-liter volume that is said to be the industry’s lowest closed-circuit breathing resistance at all work rates. The system vents only used air, reducing overall oxygen need and demand valve usage. A patented CO2 scrubber uses solid disposable cartridges that allow absorbent replacement in less time than other rebreathers. Quick-change refreezable cooling canisters have twist-off lids that change in seconds while the unit is being worn and maintain positive pressure during the switch. Body-contouring positions weight on the hips for maximum comfort. Uses Scott AV-3000 face piece with dual voicemitter and six-point quad adjustment harness. Biomarine Inc., div. of Neutronics Inc., Exton, Pa.