Sentinel XL™ CBRN is a high performance PAPR designed to meet the needs of first receivers and other first responders. Incorporates a unique "lay flat" butyl hood designed to stow in a NIOSH approved backpack. System is NIOSH approved in a belt mounted configuration. Blower delivers high flow rates and incorporates a low voltage alarm/light to alert the user when approximately 30 minutes of acceptable battery performance remains. System is convertible to infectious disease applications through change of hood/hose and filters.