Smart Bike Helmet，it is a Multi-fonction bike helmet: Bluetooth bone conduction headphones with mic can hands-free phone call,play music; Built-in wind protection goggle.conduction bluetooth headphones conduct sound to the cochlea through heekbones by vibration. Listen to your music or make phone calls and your surroundings simultaneously .

specifications: 

• Type: Integrally-molded Helmet
• Material: PVC
• SIZE: M/L
• M: 54-58cm
• L: 58-62cm