product feature : 3-setting eq 10-hour lithium battery miniusb charge removable belt clip 3.5 mm input and output detail : - sound test : work pretty well with earphone \/ headphone , noticeable increase in quality of sound and bass response ! - build : the design and build have improve a lot and have a blue \/ red led indicator and a belt clip - value : at the current price this be worth it , increase sound output - Summary : recommend for user : at the gym \/ on flight \/ at a noisy place ... etc also check out the fiio e17 if you look for something higher as this be just a basic headphone\/earphone amplifier !