The Portable Wooden Mini Speakers use an environmentally friendly rechargeable lithium ion battery for power, so you won't need to spend time looking for an electrical outlet to get the music started. The speakers are made from bamboo and wood. They are incredibly durable and in three different colors: the pale White Bamboo, the medium brown Zebra Wood and the dark chocolate brown Walnut Wood. The Portable Wooden Mini Speakers measures 2 inches in height by 2 inches in width by 2 inches in depth, making it small enough to fit in your pocket. The speakers can be used with any type of digital music player, including all generations of iPods. You can also use it in place of earphones with portable CD players that include USB ports.