The Sennheiser SK 100 G4-B is a robust bodypack transmitter for the evolution wireless G4 100 series, used daily on stage, in theatre, conferences and houses of worship with clip-on (lavalier) and headset microphones, or with an instrument cable for guitar and bass. This B-range version covers 626 - 668 MHz. It offers up to 42 MHz of switching bandwidth with 1,680 selectable frequencies and up to 20 compatible channels, plus infrared synchronisation with the matching G4 receiver for fast setup. RF output is up to 30 mW depending on local regulations, and range is up to 100 metres. The 3.5 mm locking input accepts microphone and line-level sources, with an audio frequency response of 80 - 18,000 Hz for microphones and 25 - 18,000 Hz at line level. Signal-to-noise ratio is at least 110 dB(A). It runs typically 8 hours on two supplied AA batteries, measures approximately 82 x 64 x 24 mm and weighs 160 g. Microphone not included.