Features 1、Microphone Amp: High sensitivity, ALC automatic level control, 1000 times amplification, which allows you to hear weak sounds. 2、Practical Uses: Directly drive headphones to listen, can be connected to mobile phone recording, and the interface is 3.5mm. 3、Reliable Works: With premium aluminium alloy shell, small size and exquisite appearance, stylish and powerful. 4、Better Designs: This stereo switch box ensures lossless signal as well as strong anti interference performance, very reliable. 5、Smart Carrying: Comes with a compact size of 65 x 53 x 25mm, both the storage and carrying are very convenient. Specification Item Type: Microphone Amplifier Product Material: ABS, aluminium alloy. Power Supply: DC 5V Interface: Approx. 3.5mm / 0.14in Battery: 250mAh 502030 lithium batter, with built in battery. Package List 1 x Microphone Amplifier 1 x Power Cord 1 x Headphone Cable