JOTRON Batteryless Telephone System – BTS 4000 System BTS 4000 is an emergency telephone system without the requirement for any external power supply.

JOTRON Batteryless Telephone System - BTS 4000 System BTS 4000 is an emergency telephone system without the requirement for any external power supply.

JOTRON Batteryless Telephone System – BTS 4000 System BTS 4000 is an emergency telephone system without the requirement for any external power supply.