Bell Transitions Photochromic Shield for ClickRelease helmets - One Size Shield tints automatically and quickly adapts to lighting conditions Shield is clear at night and in low light and tints darker as light brightness increases Darkens from fully clear to dark tint in about 10 seconds in bright sunlight Bell NutraFog II antifog coating reduces fogging Anti-scratch and UV-protected coatings block 100 percent of UV rays