Features:
All call adaptor and amplifier
Provides a 4 stroke chime from door station
Music and All Call volume controls
Music and chime distribution switches
Music Bass and Treble controls
Music On/Off master switch
Will function in any LEF or LEF-C system to provide background music and chime form door
Provides All Call in any LEF-C system and in systems incorporating the LEF-10S

Aiphone BG-10C Information: http://aiphone.com/home/assets/Uploads/downloads/documents/products/specs/BG-10C-SS.pdf

Specifications:
Power  source: 12V  DC,  2.5A.  Use PS-1225UL. (Powers LEF system and BG-10C.)
Current  Consumption: 100mA (Standby) Max. 2.5A (Music, Chime & All Call)
Output: 800mW @ 20 ohms per station, 11  stations  max.
All Call Initiation: From any LEF-C master or sub master. Also  from  LEF-10S.
All Call Reception: Any LEF series master station. LE-C, CN sub stations. Other LE series sub  stations  with  capacitor  (NP-25V).
Chime  Initiation: Any LE, LS  or MY Series door station; Maximum 3. MY series door stations require video adaptor.
Chime Reception: All LEF series master stations. LE-C, CN sub stations. Other LE series sub  stations  with  capacitor  (NP-25V).
Wiring: Multi-conductor  with  overall  shield.
BG-10C to LEF: 19 Conductors (Use Aiphone #822220)
BG-10C to LE Series Door station: 3 Conductors (Use Aiphone #822203)
BG-10C to MYW-P3L: 7 Conductors (Use Aiphone #822210)
Wiring  Distance: (Between  BG-10C   and farthest LEF) 650’  w/22AWG;  1600’  w/18AWG
Dimensions (H x W x D): 6-1/2” x 10” x 3”

BG-10C; All Call, Chime adaptor shall only be included in Master Sentry intercom systems.
The unit shall include Music, Chime, All Call and all Call pre-tone volume controls, music tone and bass controls.
Individual station switches to control music and  chime  distribution  to  each  station.  A  separate switch shall be provided to switch music on or off to all  stations.
The BG-10C shall operate using a 12V DC, 2.5  Amp power  supply.
The  BG-10C  shall  provide  800  mW @ 20 ohms per station to up to eleven stations. 10 Watts maximum. Any LEF-C and the LEf-10S shall
have the ability to initiate an All Call. All LEF series masters shall receive the All Call, chime and music.
LE-C  and  LE-CN  sub  station  shall  receive  the  all call, chime and music. Other LE series sub stations shall  receive  the  all  call,  chime  and  music  with  the addition  of  a  capacitor.
The  BG-10C  shall  surface  mount  to  a  wall  or  be placed on a desk or shelf.
Wiring  shall  be  multiple  conductors  with  an  overall shield  inside  a  single  jacket,  including  eight  (10) common  wires,  plus  one  (1)  individual  wire  per station in the system.  Maximum 19 conductors.
Manufacturer must have earned  ISO 9001 certification  for  quality  standards.