The Auteldac 5 (A5) telephone is aweather resistant unit, designed to withstand arduous industrial atmospheres and environmental extremes. Safe operation in hazardous areas, the Auteldac 5 carbon loaded glass filled polyester enclosure eliminates risk of rust and corrosion. Features include ’electronic on-hook sensing’ and ’electronic tone ringer’. Should the handset be left off-hook, the A5 will automatically revert to on-hook state after a period of 7 minutes (optional). Auteldac 5 telephones come complete with an integral ringer with volume control and secondary beacon / external sounder actuator as standard. An inductive coupler is fitted to aid the hard of hearing.