Specifically designed for the long-term home use, the LIFECARE PLV-100 is a reliable, easy to use portable volume ventilator. The PLV-100 is a versatile device that's effective on a wide range of patients including pediatric patients and patients with minute ventilation demands. The audible alarm ranges between 70 and 85decibles (at 1 meter) and has its own power sourceseparate from the internal battery. Completely refurbished by BemesOnline.com. The power source and batteries are constantly recharged with a 2 amp trickle charge when the unit is plugged into AC power, whether it is operating or not.