Guardian Telecom WRR-11-H/ WRR-41-H Hazardous Area Ringdown Telephones Features: Attractive reed connect switch to reduce components subject to wear Exemplified build immune to water moisture build-up or condensation and dust Joint turns on plastic bushings to avoid performing caused by sodium or corrosion Spring-loaded door for automatic closure Rise arrestor to prevent current increase damage Robust professional handset Electret disturbance reducing mic for clear communication Temporary. range -40 to +60 C (-40 to +140 F) Waterproof relationships & metal accessories for longer life Compact durable box with growing plate Clam shell components for easy service Hearing aid compatible Electronic ring for reliability Weather, dirt & deterioration tolerant for any detrimental area application Easily connected to any single range analogue CO or PABX telephone line Precious metal dust protected faceplate to remove corrosion Front access menu for ease of hook-up