Algo 8028 SIP Door Phone / IP Intercom Single pair 24 AWG wiring up to 1,000 Ft (300 m) between door station and controller for easy new or retrofit installations Flush or surface mount (i.e., dual gang) weather-resistant enclosure Choose Stainless Steel or Brass Faceplate; Both are included Backlit call button; Configure device settings via Web Interface SIP compatibility with all leading UC vendors including: Avaya, Broadsoft, Cisco, Digium/Asterisk, Mitel, Metaswitch, NEC, and Polycom and most others