Sennheiser Earset 4-ew-3 - Headworn Vocal Microphone For Stage and Broadcast Use Extremely small and lightweight for ease of handling Insensitive to the penetration of sweat and moisture Based on the proven acoustics of the MKE 1 sub-miniature clip-on Microphone High maximum sound pressure level and excellent speech intelligibility The components of the ear-worn microphones are easily interchangeable.