The Cisco 8851/8861 Key Expansion Module with Multiplatform Firmware supports third-party call control (SIP) on supported open SIP, third-party UCaaS voice and video platforms. It uses exclusive multiplatform (MPP) firmware and does not work with Cisco call control. It adds 14 programmable buttons to your Cisco 8851/8861 IP phone equipped with Multiplatform firmware. Two page buttons allow you to take advantage of a total of 28 additional buttons. The large LCD display provides quick and easy identification of associated buttons.