The Weatherproof and explosion-proof telephone secondary bells are designed for indoor and outdoor use in industrial applications with explosive atmos pheres, e.g. the petrochemical industry.
The tested high quality of the materials we use allows these devices to be used in extreme conditions in EEx II-classified applications. The user can select between a single-tone, two-tone, three-tone or warble tone ring with the help of internal DIP switches.
Four different tone sequence frequencies can also be selected in a range between 5 and 20 Hz.

Please see below "ORDERING INFORMATION" for product diffrent options and relevant part numbers.