The characteristics of the SR 500 are as follows: The battery is of lithium-ion type • Two battery alternatives, i.e. STD (Standard 2.25 Ah) and HD (Heavy Duty 3.5 Ah) • The charging time for the Standard battery is around 1.5 hours and for the Heavy Duty battery, about 2 hours • Equipped with two filters/combined filters • Operating time of up to 13 hours • The same control is used for starting, stopping and selection of operating status • Display with symbols • Equipped with automatic air flow control with compensation for air pressure and temperature • Can be used together with hoods SR 520, SR 530, SR 561, SR 562, SR 601, SR 602, SR 604, face shield SR 570, welding shield SR 570/SR 574, half mask SR 900, full face mask SR 200, welding shield SR 592, helmet with visor SR 580 or welding shield/helmet with visor SR 584/SR 580. Electronics ingress protection is approved in IP class IP67 according to IEC / EN 60529. The SR 500 is also available in an explosion-protected version designated the SR 500 EX for use in a potentially explosive atmosphere. See the separate product leaflet.