【Mini Size but Powerful】-- Don't be fooled by its size, it’ll give your entertainment system a serious boost. With 2.1 channel output RMS 20W×2(L/R)+40W(subwoofer), which can drive most home/car/marine/outdoor passive speakers and subwoofers, and with excellent sound. Low distortion, acoustically accurate reproduction of music, which sounds smooth and full.【Bass & Treble & Sub Vol Control】-- Designed with main volume, treble and bass control knobs, Which for more delicate adjustment of the sound, much fun and high playability. Besides main volume, treble and bass control, sub volume control is specially designed. They allow you to control the volume of passive Subwoofer and two passive speakers separately as you wish.【RCA & AUX Inputs】-- With standard stereo RCA and 3.5mm AUX inputs, can be compatible with various devices, such as mobile phone, MP3, MP4, CD player, TV, computer etc. Just enjoy your music the way you want to. Besides, there's a little blue woofer alert that turns on when the woofer is beating.【Portable & Convenient】-- Mini Size: 5.9x3.6x1.4" / 15x9.1x3.7cm, amplifier weight: 0.66 pounds/ 0.3kg. Compact design with exquisite appearance, matt black case looks fashionable and durable, unique structure design easy to be installed in car, marine, RV, golf cart or home, which save space and convenient to operate.【Great Value Choice】-- The package comes with a Facmogu DC 12V 3A adapter valued at over $10, which makes purchasing this ST-838 amplifier a very good deal. You don't have to find a adapter with 5.5x2.5mm plug in your pile of old power adapters or pay for another one. Besides, just enjoy peace of mind with 12 months Warranty & product support & excellent customer service.