What's in the box:

HIFI Level with Filter Digital Power Amplifier Board Module 50Wx2 AUX and BT Audio Input 2-in-1 Stereo Audio AMP with Volume Control Knob and Switch (Black)

This is a cost-effective audio power amplifier specially designed for HIFI sound. Good quality with affordable price.

Features:
Made of good materials, delivers high performance. A cost-effective power amplifier for HIFI music.
Employ TPA3116D2, a Class-D stereo amplifier IC with high performance. The modulation frequency can be up to 1.2MHZ, and >90% power efficiency combined with low idle loss greatly reduces heat sink size.
Equipped with BT 5.0, transmit farther and more efficiently.
With AUX and BT two ways of audio input, 2-in-1.
The potentiometer with a switch for easy control of the volume, making it ideal for DIY speakers.
Filter inductor makes the sound mellow and clearer.
Integrated self-protection circuits including over-temperature, short circuit, over-voltage and under-voltage.
Comes with DC lead, compatible with the power input interface of this product, even if you don't have a DC adapter or battery, it can be easily wired.

Note:
1. Only when the audio input is sufficient and the power supply voltage/current is sufficient, will there be enough output power. The higher the power supply voltage, the higher the relative power. The speaker with different impedance will have different output power. In the case of sufficient voltage and current, the larger the ohm of speaker, the smaller the relative sound power.
2. The switch on the board is for control of standby mode. When turn off the switch, the unit is in a low-power standby state. If you want to completely turn it off or you may not use it for a long time, you can just unplug the DC cable.
3. The heat sink needs to be pasted onto the chip by yourself. The hotter the glue, the better the thermal conductivity.

Specifications:
Material: ABS
Color: Black
Model: ZK-502C HIFI
Chip: TPA3116D2(with AM avoidance)
BT version: 5.0
Output power: 50W x 2
Allowable supply voltage: 5~27V (optional 9V/12V/15V/18V/24V adapter, high power for high voltage)
Compatible speaker: 30W-200W, 4O,8O
Number of channels: left and right dual channel(stereo)
Transmission distance: 15 meters (without barrier)
Protection measure: over-temperature, short circuit, over-voltage and under-voltage
Power supply voltage: 12V, 8Ospeaker/12W (left channel) + 12W (right channel), 4O speaker/20W +20W
15V, 8O/18 +18W, 4O/ greater than 30 + 30W
19V, 8O/32 + 32W, 4O/ greater than 45 +45W
24V, 8O/38 + 38W, 4O/ greater than 55+ 55W
Item Size: 9.8 * 5 * 1.5cm / 3.85 * 1.96 * 0.59in
Item Weight: 46g / 1.62oz
Package Weight: 115g / 4.05oz
Package Size: 11 * 6.5 * 5cm / 4.33 * 2.55 * 1.96in

Packing List:
1 * Amplifier Module
1 * Heat Sink
1 * Screwdriver
1 * DC lead
1 * Shell
1 * Knob