Bullard's PA30 Series Powered Air Purifying Respirator (PAPR) utilizes nickel metal hydride batteries for 8-10 hours of performance, while eliminating the "memory" concern that reduces overall battery service life in other PAPRs. Voltage regulation circuitry assures consistent airflow (8.5 CFM) throughout the work cycle, and an audible alarm indicates low voltage.Bullard, Cynthiana, KY.