MT-91 Dynamic Type 1 Transmitter - Type : Dynamic Type Transmitter - Response Range : -66 ± 3.5dBV(300-3300Hz) - Frequency Response : 1KHz: -66 ± 3.5 dbV - Impedance : 150 ± 30 ohm - Electrostatic Discharge : Breakdown Volt. 15KV.Min - Weight : 34 grams ( 1.2 oz ) - Dimension : (Ø) 35mm x 20.8 mm - Screw terminal