With three snaps, the middle snap fastener is fixed, and the four snap fasteners on both sides are grooved.
The four snaps on both sides can slide, and the sliding space is about 3cm, which means that this lens can be suitable for helmets with three snaps, various half helmets, and 3/4 helmets.
One size, suitable for all helmet.
The optical refractive index, light transmittance and are in compliance with EU standards and Japanese JIS standards.