I was pleasantly surprised by this little amp. The sound is really clear, and it doesn't introduce any noticeable hiss until the master volume is cranked all the way up (which would deafen you with almost any source, so not exactly a big deal). It has it's own master volume and EQ controls, which is sweet. Plus it's super small, sleek, and seems pretty durable. Overall, it's a real nice amp if you want to improve the output & sound of your headphones without spending a ton of money

Pros:
-Rechargeable battery
-Good quality sound
-extremely underpriced
-sleek look, feels decently built

Cons:
-Controls are a little confusing at first
-poor labeling
-Plastic clip is fairly cheap (they do include 2)