Review on Portable Headphone Amp With 3.5Mm Stereo Audio Out, GAIN Support & Lithium Battery - Compatible With IPhone/Cellular Phone/MP3/MP4 /Computers. by Doug Bundy

What i like: it has rechargeable battery that lasts a good while. Its small and easily fits in my glove box. It can boost the low frequencies, or the high frequencies. Micro USB makes finding a charger easy.What I don't car for: I forget to turn it off all the time and go to use it and battery is dead. I know its my fault, but an auto turn off would be nice. When boosting the high frequencies, it lacks in the bass area big time. And if you have a system in your car its a big deal.Overall: first of all its nice and worth it. 99% of ppl would be more than happy with the product. It deff boosts the sound in my Mercedes-Benz much louder. My aux input is so quiet for some reason. And its in my glove box so I forget to turn it off all the time. But its a great overall product.