Features LOSSLESS AND INTERFERENCE RESISTANT SIGNAL: This is a stereo switch box with lossless signal, solid aluminum alloy shell with strong interference resistance. Better Equal Sound Circuit:When you listen to music at low volume, you feel the treble is low and dull, and the bass is small and low. According to the characteristics of human hearing, the equal sound circuit increases treble and bass at low volume WIDELY COMPATIBLE WITH ALL AUDIO DEVICES: Suitable for DVD, CD, set-top boxes, MP3, TVs, mobile phones, computers, tablets, turntables, sound cards, guitars, bass, electronic musical instruments, game consoles or other devices. 3.5MM OUTPUT: This fader input and output are stereo, usually used to control small signal controls, installed between the audio source and the preamp or between the preamp and amplifier, strings in the audio loop. Small and Portable: The mini stereo audio preamplifier has a small size, easy to carry and use. The size is 88mm (L) x 38mm (W) x 38.5mm (H) Specification: Item Type: Mini Stereo Audio Preamplifier Input: 3.5 mm. Output: 3.5 mm Size (L x W x H): approx. 88 x 38 x 38.5 mm/3.46 x 1.5 x 1.52 inches. Package list: 1 x Mini Stereo Audio Preamplifier Package List 1 x Mini Stereo Audio Volume Controller