CEP-26 Expansion Module has been designed to improve the flexibility and productivity of advanced CooFone-D60 IP Phone. It adopts 26 programmable DSS keys for strenthening the IP Phone features to meet the requirements of executive and administrative staff who require high call coverage and flexibility from communication systems. Three(3) colors LEDs of each DSS key is helpful to indicate the working status. It allows daisy-chain up to five(5) modules, so you can use 150 programmable keys, call coverage and management is even more easy and efficient to handle.