Promino Road Bike Helmet Cycling Helmet with Retractable Polarized Lens Integrated Combined sunglasses with helmet to solve the troubles of myopic riders With 3 different retractable lens that you can adapt to various of weather and environment Molded by high density EPS and high strength PC, reduce the impact damage Wind tunnel ventilation with 25 vents, special chin pad, more comfortable Adjustable knob to control the head circumference