Valcomft. s V-9940 Expandable station level page adapter features Full-Featured Paging From Centrex or Standard C. O. Line Can Be Use With Valcom Multi-Zone or Talkback Page Controls Multiple Units can be Linked Together For a Common All Call UL Listed Access: Connects Directly to Selected PBX Station Port Centrex or a C. O. Line(FCC Registered); Specifications: Input Impedance: 600 ohm; Music Source Impedance: 4 to 600 ohm; Music Input Level: -10 to -18 dBm Nominal; Power Requirements: -24 Vdc/200 mA Shipping Weight: 2.0 lbs (0.91 kg)Dimensions: 8.2in. H x 4.55in. W x 2.3in. D (20.82 cm x 11.55 cm x 5.84 cm)