The Avaya SBM24 Button Key Expansion Module 700462518 is designed for use with the 9600 Phone system. It provides 24 additional phone lines and features Power Over Ethernet (PoE) for convenient power supply. This expansion module, manufactured by Avaya in China, utilizes an Ethernet (RJ-45) interface for connectivity. Perfect for businesses looking to expand their VoIP phone system with a reliable and high-quality Avaya product.