High Quality Stereo Sound - Battery Capacity: 800mah.Supports Micro SD Card (Up To 8 GB) To Play Back Mp3s - Speaker Power: 20 Watts.Built-In Rechargeable Lithium Battery - Construction Material: Metal.Headphone Jack for Private Listening - Dimensions: 3.5'' X 3.5'' X 3.7''.Charges over USB - Just Connect To Your Computer The PLBSK30BK is a small, portable bicycle & sport speaker. It's so compact, you can take it everywhere you go. This little speaker provides high-quality, stereo sound, and suppors micro SD cards up to 8 GB to play back MP3s. The built-in rechargeable battery means you can simply plug this device into a USB port to charge up for your next adventure. You can even plug in headphones when you want a more private listening session. With 20 watts of sound, the PLBSK30BK packs a big punch in a small package. Color: silver.