Speaker works with any 3.5 mm headphone jack, perfect for laptops, phones, portable game devices, MP3 players, etc.Size defying sound - Vacuum bass design provides surprising volume and bass response in a small space-saving speaker that fits in your hand.Built-in rechargeable battery - Long-lasting rechargeable internal lithium ion battery.Collapsible speaker can be used singly or get two for simulated stereo - Twist speaker to expand.Use two for simulated stereo or a single speaker for mono.Audio plugs for connecting to audio source so you can charge speaker while listening.Speaker works with any 3.5 mm headphone jack, perfect for laptops, cell phones, portable game devices, MP3 players, etc The iHM60 is an amazing approach to audio that offers size defying sound. Speaker connects to a computer or other USB power source via the included USB cable to recharge the internal lithium ion battery. Remarkable vacuum bass design delivers surprising volume and bass response in a speaker that fits in your palm. Perfect for laptops, cell phones, iPhone, iPod and other MP3 players (any device with a 3.5mm headphone jack). Available in 3 translucent colors.