Check the listing for details. COMMAX 12-Buttons Audio Intercom Door Panel for Apartment DR-12AM. Condition: New. Listed at 189.00 USD. COMMAX APARTMENT AUDIO INTERPHONE SYSTEM12 BUTTONS AUDIO DOOR STATION DR-12AM DR-12AM: 12 Buttons Audio Intercom Panel. Door Entrance Unit. COMMAX Door Station compatible with various systems provides you better efficiency to the system and guarantee more secure an comfortable life. Features:Function: Call residential station for up to 12 residential stations/ name card.House call & TalkConnectable product: DP-KSS, DP-SS, DP-MLMaterial: Aluminum panel/ Flush mount typeWiring: Common 3 wires, Individual 1 wire per Unit.Power Source: DC 12V (RF1A or RF-12015S) Wiring Diagram: *** Diagram for reference only. Actual product may be different. Please contact us if you have any question. ***Wire***CAT5 UTP cable is not recommended for audio intercomThe recommended cable is AWG18 (for long distances up to 100 meters/300 feet), the minimum recommend cable is AWG20 (for distances less than 70 meters/210 feet).According Commax specifications for audio intercom, the wire gauge to be used is as follows:Transmission Distance(feet)Transmission Distance(meters)American Wire Gauge(#AWG)Diameter(mm)9030240.515050220.6521070200.8300100181 Compatible connectable products: Room unit DP-SS AC-110V to DC12V power adapter RF-1A Power adapter AC110~240V to DC12V RF-12015S Also available in set 12-Apartment Set