Audio 2000's AWM6112 Plug-In-N-Recharge VHF Dual Channel Wireless Microphone System Series: VHF Type: Wireless Microphone Systems Specification: Carrier Frequency Range:  VHF Band Frequency Stability:  ± 0.005% Modulation:  Frequency Modulation (FM) Modulation Depth:  30KHz Output Power:  30mW, Max Harmonic Suppression:  40dB Battery:  AA Batteries X 3 (1.5V X 3) Current Consumption:  75dB Max. SPL:  >100dB T.H.D.:  Channels: 2