The extension Keypad is designed for the Remote Call Station RK-MIC to increase its number of physical keys. It can help users to efficiency of manual operation. The function of the keys can be configured improve the as zone selection, group selection, broadcast task selection, volume control or zone close, etc. Each Remote Call Station can connect up to 8 units of HMC-K8 and each HMC-K8 has 8 Keys and 8 indicators LEDs. Features Power supply from RK-MIC Flexible label slot with changeable labels Support rack mount or desktop flush mount Eight configurable keys Each RK-MIC can connect up to 8 extension keypads EN54-16, CE & CB Complied A two-color LED indicator for each key