At 12" x 8.4" x 8.6", this is one smart little speaker. Stream music wirelessly from Bluetooth® enabled audio devices such as smartphones, tablets, computers and more, or you can also use the 3.5 mm auxiliary input and included cable to play audio from devices without Bluetooth®. The auxiliary cable also functions as an antenna to allow you to use the speaker as an FM radio and you can plug in a USB flash drive or Micro SD card to play your music. Built-in controls include play/pause, forward/backward track and volume. Specs are: Play time: up to 2.5 hours (max. volume), up to 6 hours (moderate volume); charge voltage: DC5V (USB); battery: 3.7V/1800 mA; FM frequency: 87.5-108MHz; weight: 6 lb 8 oz.