AK 170: Features: Mini HIFI Audio Power Amplifier. Two main channel outputs. The left and right channel outputs are speakers or speaker connectors. Low distortion for clearer, stronger, more powerful sound. The body is made of aluminum alloy, which is thick and feels very good. The big knob is designed with blue LED light, which makes the product more beautiful. AK380: feature Multiple audio inputs: In addition to Bluetooth 5.0/stereo RCA/3.5mm AUX input, it is compatible with mobile phones, MP3 players, CD players, data players, computers, decoders, etc. It is also compatible with USB (U disk)/SD Card/MMC Card/FM radio input, which can be used as a music player and radio to easily enjoy high-quality music at home or on the road. Rated 40W+40W Output Power: Speakers supporting 4-16 ohm impedance, perfectly matched with most home and car and marine speakers to power your entertainment system with unparalleled sound advantages, allowing you to enjoy high quality amplification audio. The DC 12V operating voltage is suitable for many places: in addition to being used in a home desktop sound system, it can also be used in your car, boat, RV, golf cart - anywhere you need a great amplifier with low distortion and acoustically accurate reproduction of music . Powerful perfect design: with volume knob, treble and bass control, easy to get more detailed sound. The LED display screen is designed to clearly display the working status in real time, and it is equipped with a remote control, which is more convenient to use and is very suitable for indoor and outdoor audio systems. AK370: Mini HIFI digital bluetooth audio power amplifier. Aluminum alloy body, durable, the body is made of aluminum alloy one-time molding, anode surface treatment, the overall atmosphere, thick, feel good. It is suitable for SD card, U disk, AUX input, MP3 format playback, and supports Bluetooth wireless connection. FM stereo radio is supported. Low distortion for clearer, stronger, more powerful sound. With remote control function. Two main channel outputs. The machine supports Bluetooth operation and line input.