Sennheiser SKM 100 G4-S Handheld Transmitter

The SKM 100 G4-S is the handheld transmitter body for Sennheiser's evolution wireless G4 100 Series. It is the same lightweight aluminum handheld as the standard SKM 100 G4 but adds an integrated mute switch, so a presenter or vocalist can silence the mic on the fly without walking off to the receiver. The capsule is bought separately, letting you thread on an e835, e845, e865, e935, or e945 head to match the voice and the room.

Inside, it runs wideband FM across a UHF switching bandwidth of up to 42 MHz, with up to 1,680 tunable frequencies for finding clean spectrum in a crowded RF environment. It puts out up to 30 mW of RF power and runs about eight hours on two AA batteries or a rechargeable BA 2015 accupack.