The PA20 Series provides particulate protection for 10 full hours using a Tychem Hood or Loose Fitting Facepiece. The HEPA filter and NiMh batteries are located inside the blower unit. The PA30 Series provides protection from a wide range of contaminants using Tychem Hoods and Loose Fitting Facepieces. The PA30 uses a series of external canister-type filters/cartridges and removable NiMh batteries. The PA30IS is an intrinsically safe version of the PA30 series, designed to protect workers in some potentially explosive atmospheres. The PA40 Series provides protection from a wide range of contaminants using Bullard's comfortable Spectrum full facepiece. The PA40 uses a series of external canister-type filters/cartridges and removable NiMh batteries. Not available in Europe.