The size only 3.5*3.5cm. It may be the smallest wireless speaker in the world,You can easily put it in your pocket, hang it on your phone or backpack and take it wherever you want. he volume is definitely bigger than all current mobile phones, this mini bluetooth speaker allows you to enjoy a clear, well-balanced, full-range listening experience in camping, picnic and room. All-in-one nonfunctional button lets you enjoy music / hands-free calling / camera remote shutter functions by a single press. The speaker is compatible with most devices that have Bluetooth connection enabled, or any smartphones for that matter.