Mini HIFI Headphone Amplifier Portable Earphone AMP 3.5mm with Audio USB CableFeature：16-300Ω Mini HiFi headphone amplifier, It is delicate, compact, lightweight, and portable that it can be carry conveniently.3.5mm AUX input and output, SNR>100Db and THD+N 0.0003%, make it possibility to output not just louder sound, but a sharper and more real stereo sound without distortion.Two-stage gain switch enhances the signal input into the amp circuit for optimal performance of the headphones.Aluminum matte surface, fashion design provides you a comfortable handheld feeling while the aluminum matte surface makes it durable.Rechargeable lithium battery, it adopts a rechargeable lithium battery with 1000mAH capacity, which allows it to stay working more than 8 hours.Universal compatibility, it can remarkably compatible with a various of digital devices, such as MP3 MP4 mobile phone computer.Specification：Lithium battery capacity: 1000mAHAmp using time: more than 8 hoursAmp battery voltage: DC3.7V - 4VAmp internal working voltage: ±4VSNR>100DbTHD+N 0.0003%Output Power: 40Mw in Impedance 16ΩAdapted Headphone Impedance: 16-300ΩDimension: 95 x 61 x 13(L x W x H) Package Content:1 x Headphone Amplifier1 x USB Power Cable1 x Audio Cable1 x User's ManualShippingPaymentReturn & Refund policyFeedbackCustomer Support - ContactShippingFREE SAME BUSINESS DAY MONDAY- FRIDAY SHIPPING FROM USA.All orders and payments received before 4PM EST (1PM PST) will be shipped the same business day.All other orders within 1 business day.No shipping on Weekends or US Public Holidays. No responsibility for any custom dutyShipping information will be updated when available.PaymentWe accept payment via PayPal. Use PayPal at checkout to pay with credit or debit.Immediate payment is required. Shipping will be arranged within 1 business day once payment is cleared.Return & Refund policy1.We stand behind our items and offer 60 dayswarranty. All items are in new and working condition unless specified otherwise elsewhere in the description.2.All Returns - defective or otherwise - MUST BE PREAUTHORIZED to guarantee refund or exchange. Please contact us to get an authorization and return address. 3.Buyer agrees to pay for the cost of re-shipment for undeliverable or wrong addresses. 4.Buyer is responsible for Return Postage as well as a 20% restocking fee if return/replacement is not a result of our mistake such as wrong item.5.Replacement or Refund will be made upon receipt of the returned item. Please include tracking number so we can process ASAP. If you do not wish to wait for a replacement, please repurchase the item. 6.ALL REFUNDS will be processed via PayPal. Please double check via PayPal history and transaction for confirmation. PayPal will send it back to whatever you used to pay within 3-5 days.FeedbackWe strive to provide the best products and services. Your positive feedback 5 stars DSR help us do better. If anything about your transaction did not meet expectations, please CONTACT US and give us the opportunity to make things right. We are always here to help.Customer Support - ContactPlease do not hesitate to CONTACT US. You can message 24/7 on eBay for all questions and inquiries. We will get back to you within 1-2 business days at the latest.