The Proviz REFLECT360 waterproof helmet coveris adjustable and designed to fit over all standard size cycling helmets. It is made from 100% reflective material, it is fully waterproof, seam-sealed and lightweight. It is elasticated round the edges which can be adjusted to ensure a secure fitting around your particular helmet model and the reflective materials helps to ensure your position on the road is more easily seen at night. It is perfect for commuting in wet winter weather. About the fabric: The fabric used for the REFLECT360 range is highly technical. During daylight it is a modest grey colour. At night, when the fabric picks up an external light source, eg vehicle headlights, it gives 'astonishing reflectivity' (quote: Cycling Active Magazine). The material is CE EN 20471 certified. Wind and waterproof | Seam-sealed - for sewing line waterproofing | Made from 100% reflective material: CE EN 20471 certified | One size - adjustable drawstring to ensure a good fit around your helmet