This nickel Shure RPW188 Wireless Head replaces a damaged or faulty element on a KSM9 handheld condenser microphone. It features dual 3/4" gold-layered, low-mass Mylar diaphragms and switchable cardioid and supercardioid polar patterns for flexibility in a wide variety of performance applications. The capsule's 50 Hz to 20 kHz wide frequency response enhances vocal character.