Provides Tandem All Call Background Music Input, Automatically Mutes In Zone Being Paged Page Override For Special Or Priority Announcements Features Are Programmable Per Zone Built-In Tone Generator For Night Ringing, Time Clock Tone, Door Bell Accepts Pulse Dial And Tone Dial Battery Back-Up Input (VPB-260) To interface with analog extension or Centrex line add the V-9970 UL Listed/CE ACCESS: Page Port on Selected Telephone Systems, PBX Loop Start or Ground-Start Trunk Port, Electronic or 1A2 Line Key (line card required), or Dedicated Single Line Phone Set. Specifications: Input Impedance: 600 ohm Music Source Impedance: 4 to 600 ohm Music Input Level: -10 dBm nominal DC Output: -24 Vdc @ 500 mA Power Requirements: 230 Vac/.5A or 120 Vac/1A Weight: 6.25 lbs (2.84 kg) Dimensions: 7.1" H x 10.0" W x 3.0" D (18.0 cm x 25.4 cm x 7.62 cm)