Part: EK IEM G4-A1. The receiver is the Sennheiser EK IEM G4. Sensitivity is < 4 microV, 1.6 microV (typical) for 52 dBArms S/N with HDX engaged at peak deviation. The receiver features 20 fixed frequency banks with up to 16 compatible frequency presets and 6 user banks with up to 16 user programmable frequencies.