58000-040APO Discovery Open-Area Voice Sounder VID - White Body (Red Flash) - Isolating58000 040APO Discovery Open Area Voice Sounder VID White Body (Red Flash) Isolating Discovery Open Area Voice Sounders comprise a sounder and a sounder visual indicator that have been designed to provide clear instructional messages through the Discovery protocol. They are loop powered wall mounted devices. Key Features: Four pre set message pairs Capable of up to 15 tone message pairs Low current and high volume Fully synchronised Set up and test at