Designed with an elastic adjustment buckle, the bike helmet cover can fit most cycling helmets. By using this bike helmet cover, your helmet can be protected from rain, water, snow, dust and other elements. Besides, it increases visibility and safety at night due to the use of fully reflective design. It is made of soft polyester pongee surface and reflective material, which is comfortable and breathable. The applicable head circumference of the product is 85cm ± 2cm. Helmet cover is a great choice for cycling. Item Name: Bike Helmet Cover Material: Polyester Pongee Surface, Reflective Material Size: One Size Applicable Head Circumference: 85cm ± 2cm Features: Waterproof, Ultralight, Reflective Size Details: Applicable Head Circumference: 85cm ± 2cm/33.46" ± 0.79" (Approx.) Notes: Due to the light and screen setting difference, the item's color may be slightly different from the pictures. Please allow slight dimension difference due to different manual measurement. Package Includes: 1 x Bike Helmet Cover (Others Not Included)