The C 901ES-RF is a rigid stem cardioid microphone with a knuckle joint and 3 pin XLR termination fitted with a magnetic operated reed switch for silent switching. 195mm long in satin black. It is Designed for for use in conference halls, schools, colleges, places of worship, board rooms.The Electret condenser cardioid microphone is fitted with a knuckle joint giving horizontal and vertical adjustment. The microphone is constructed from high quality brass construction and is fitted with a phantom power adaptor accepting 9 to 48 volts DC. A magnetic reed switch is inbuilt offering silent switching. Impedance of 200 Ohms. The phantom power adaptor also includes filters which will eliminate all GSM frequencies from 800-1200 MHz.