The above relay circuits are available for: Door-strike control, when analog ports are used for Doorboxes Control for Music-on-Hold or Background Music source Control of External Paging Equipment Installs only in universal slots 1-3 of Main or Expansion Chassis. Allows addition of (1) 3-Port CO Trunk Daughter Board (3COIDB) or (1) PRI Daughter Board (1PRDB). Maximum (3) per Main or Expansion Chassis.
Maximum (9) per system. Features: Modules and Cards: Yes Dimensions (LxWxH) : 10 x 2 x 6 Weight : 1 lb.

