The SuperTooth D4 is an extraordinary speaker that  features a Bass Reflex system that will enhance basses when you stream your favorite music to the D4. The D4 was designed to be used on the go as it combines compact dimensions, light weight, and a strap to carry it easily. It has no wires and can be used with your phone, MP3 player, tablet, or computer. The D4 lasts up to 12 hours of continuous play time. The size of the D4 makes it perfect for portable use. So, take it along outdoors, to the beach, on a picnic, or anywhere you want!