Despite its mini size(can be hold with one hand), the output power is improved to 100W(50W*2) with the upgraded chip. You will be amazed by its output power compared to its size when you see it.This is Nobsound's new power amplifier in 2022. Based on our previous product, we enhance its output power and improve its functionality, while still keep its mini size and elegant design.Prompt and courteous customer service. If you met any troubles or had any questions, please feel free to contact us. ISED Certification Registration Number: 30459-M1PRO; ISED Hardware Version ldentification Number (HVIN): M1 PRO: We need to mention that with the USB input, music can be played losslessly(Like connecting with a computer. By the way, you don't need to install a driver). You will be surprised by the sound quality.Supporting AUX/USB/Bluetooth input. You can enjoy your music in different ways. The Bluetooth function is also upgraded to 5.0. Now it is more stable and faster.