Peavey 03010680 Assisted Listening System 72.9 MHz Transmitter & 4 Receivers with Earbuds (ALS72.9) Peavey ALS 72.9 MHz Assisted Listening System Transmitter And Four Receivers With Ear Buds Frequency Response 100Hz - 15 KHz, +/- 3dB Signal-to- Noise Ratio 60dB