This is a BOSS WL-20L wireless system receiver. The response is very good, and I personally didn't feel any delay. It supports a transmission distance of up to approximately 15m, so you can use it at home or for live performances. If you find the sound quality changes of the WL-20's cable tone simulation bothersome, this might be more suitable for you. It's in a clean condition, having been used only a few times. Model: WL-20L Brand: BOSS Latency: 2.3ms Transmission Distance: 15m