Model name: SPA500S-RF
32 programmable multicolored LED buttons Call transfer; Speed dial; DSS Dual images for resilient firmware upgrades The Cisco SPA 500S is a 32-Button Expansion Module that compliments the Cisco SPA 501G, SPA 502G, SPA 504G, SPA 508G, SPA 509G, and SPA 525G IP Phones. Once youve connected the SPA 500Ss simple bracket-and-cable setup to your existing Cisco IP phone, youll be able to track the status of up to 32 separate phone lines per Expansion Module. And, if you need more room to grow, you can connect up to two Expansion Modules for every phone.