This 2 x 20 Watt Stereo Bluetooth Amplifier module only measures 50 x 35 mm and is extremely powerful.
Without additional cooling (heat sink), it can crank out 2 x 20W on a 4 Ohm Speaker at 20V power supply.
The maximum operating voltage range of the 2 x 20 Watt Stereo Bluetooth Amplifier Module is 8-24V and the minimum recommended Speaker impedance is 4 Ohm.
It has controls for volume and pause/resume on board (single knob).
After connecting power to the board, it automatically starts pairing with the last know device or can connect to a new device right away.
It also features several safety features like short circuit protection, overload protection, and thermal protection.
For the maximum output power of 2 x 30W is an additional heatsink required.