The model number Sennheiser EW 100 G4-ME2/835SA1 denotes a wireless combo microphone system. This system includes a bodypack with an ME 2 lavalier mic and a handheld transmitter with an e 835 dynamic capsule. This system is suited for presenters, performers, lecturers, and anyone needing both a hands-free lavalier mic and a handheld microphone option. The "A1" at the end of the model number refers to the frequency band it operates on (470-516 MHz).