Aukey MUSE Portable Wireless Bluetooth Speaker, 10 Hour Playtime, Dual 5W Driver, Enhanced Bass, Full, High-Def. Sound, Built in Mic, 3.5mm AUX Port (SK-M2, Silver)
I was amazed by the build quality of this speaker.  The only problem its the Bluetooth.  As many others have pointed out, there is a problem with it since it starts stuttering.  Now, to be fair this is what I found so far:  It seems that Android Bluetooth in lollipop by itself have a problem. (Just search on Google), but I also found that there must be an engineering problem in the design of the speaker since it has metal all around it. (Notice that many Bluetooth non-problematic devices are mostly plastic)