Features: * Mini HIFI digital Bluetooth-compatible audio power amplifier. * TF card, AUX, U disk, MP3 format playback, support Bluetooth wireless connection. * Support FM stereo radio. * With treble, bass and volume control, it is very easy to use. * Low distortion provides clearer, stronger, and more powerful sound. * Two main channel outputs. * With remote control function. * DC/AC power input, suitable for home or car. * Upgrade high power 90W+90W. * The voltage can be switched automatically. * Low heat and light weight. AK170(No bluetooth) Color: Balck Material: Aluminum Alloy Size: 125X75X40MM Input voltage: DC 12V RMS power: 20W+20W Max power: 200W+200W Channel: 2CH Load impedance: 4-16Ω SNR: 90 db Frequency: 20Hz-20KHz Distortion rate: 0.01% Package Included: 1 x Power Amplifier Specification:(AK35) Name: Audio Stereo Amplifier Voltage: 110V Impedance: 4-16Ω Plug: US RMS power: 30Wx2 Peak power: 90W x2 Load impedance: 4-16Ω Channel: 2.0 Signal to noise ratio: 85 decibels FM frequency: 87.5-108MHz Distortion rate: 0.05% Frequency: 10Hz-20KHz Size: approx. 19x12.5x4.5cm/ 7.48x4.92x1.77'' Color: black Packing included: 1 x Power Amplifier 1 x Remote Control Specification:(AK380) Name: hifi power amplifier Material: aluminum alloy Rated voltage: 12V RMS power: 40W+40W Max power: 400W+400W Rated frequency: 20-20KHz Resolution: 47K Distortion rate: 0.1 SNR: 90dB Impedance: 4-16 Ω Interface type: clip Receiving mode: audio input Size: 155x85x45mm/6.1inx3.3inx1.7in Color: Black Packing included: 1 x Power Amplifier 1 x Remote Control Specification:(AK370) Name: hifi power amplifier Model: AK370 Material: aluminum alloy Function type: 2.0 vertical sound body Output power: 20W + 20W Power supply: 12V Impedance: 4-16Ω bluetooth distance: about 10m bluetooth: 5.0 Audio input: RCA stereo audio, storage card, U disk, USB audio input (can be connected to computer/mobile phone/OTG/tablet OTG) Signal-to-noise ratio: 90 decibels Frequency: 20Hz-20KHz Distortion rate: 0.01% Size: 125X75X40MM Colour: Black Packing included: 1 x Power Amplifier 1 x Remote Control Note: 1. Please allow 1-3cm (0.4-1.18") difference due to manual measurement and slight color variation for different display setting. 2. Due to the light and screen difference, the item's color may be slightly different from the pictures. Please understand.