Feature: 1. 16-600Ω HiFi headphone amplifier, it is delicate, compact, lightweight, and portable that it can be carry conveniently. 2. xmos chip and 9038Q2M. 3. 3.5mm AUX input and output, SNR>129Db and THD+N 0.0003%, make it possibility to output not just louder sound, but a sharper and more real stereo sound without distortion. 4.Two-stage gain switch enhances the signal input into the amp circuit for optimal performance of the headphones 5. Aluminum matte surface, fashion design provides you a comfortable handheld feeling while the aluminum matte surface makes it durable. 6. Rechargeable lithium battery, it adopts a rechargeable lithium battery with 4000mAH capacity, which allows it to stay working more than 10 Hours. 7. Universal compatibility, it can remarkably compatible with a various of digital devices, such as MP3 MP4 mobile phone computer. Specification: Model: HA4 Maximum power output:1000mW in Impedance 16Ω Load impedance: 16-600Ω Amp Internal Voltage: ±9V Charging voltage: DC5V Frequency response: 20Hz-20kHz(±3dB) Battery capacity: 4000mAh (3,7V) Lithium-Battery Amp Using Time: More Than 10 Hours Distortion: 0.004% SNR: ≥129dB Dimension: 4.5*2.4*0.6inch Package List: 1 * HA4 Headphone Amplifier 1 * USB Power Cable 1 * Audio Cable 1 * Type-C Decode Cable (We send Type-C Cable for all orders,but if you want to change into micro usb cable,please note it well in the order.) 1 * User's Manual

Note:Packing list of HA4 headphone amplifier isn't include OTG cable for Apple mobile phone.