Pureflo PR05806SP PAPR Battery Pack
The is the Gentex Pureflo PR05806SP spare battery pack for the ESM+ and ESM series of PAPR's. It is a 5 cell Nickel Metal Hydride battery delivering 6V and 2.2Ah.
They are sold by the each but Pureflo Helmets require (2) each battery packs to operate.
It also fits the older PR02000 series PAPR's. It was formerly p/n PR02030SP.