Makerhawk Mini Amplifier Board Bluetooth Amplifier 20 2X50W 5V-24V Audio Power Amplifier Module For Store Home Theater SpeakersParameter Model: ZK-502L Blue tooth Version: 50 (without occlusion 15m) Audio Input: Bluetooth channel: 20 Input Sensitivity: 500mV Adaption Supply Voltage: 5-24V Speaker: 30-200W, 4-8Ohm Protection Mechanism: self-recovery..