WINOMO Motorcycle Helmet Headphone Headset Bicycle Motorbike Mp3 Speaker 3.5mm with Volume Color: Black.Material: Mainly plastic. nterface type: 3.5mm connector.Total cable length: 186cm. With volume controller, making it easy to operate. Compatible with other devices such as MP3, phones etc with 3.5mm interface. Can be stuck to the helmet by velcro tapes.