Nady ENCORE DUET LT/O/A/F Two-Channel (A/F) Wireless Lavaliere Microphone System with Two Microphones Off/Standby/On switch allows muting the transmitter while maintaining signal integrity Dual-channel receiver with independent balanced XLR and mixed unbalanced 3.5mm jack outputs Operational range up to 500 feet LED displays for monitoring incoming signal strength and audio level Frequency response: 25 Hz - 20 kHz