Cisco Unified IP Conference Phone 8831

https://www.cisco.com/c/ru_ru/support/collaboration-endpoints/unified-ip-conference-phone-8831/model.html

https://www.cisco.com/c/dam/en/us/products/collateral/collaboration-endpoints/unified-ip-phone-7940g/prod_brochure0900aecd800f6d4a.pdf

https://www.cisco.com/c/dam/global/ru_ru/about/brochures/assets/pdfs/cisco_ip_telephony_2016_ru_s5.pdf