Electra is the first electronic eyewear that is able to adjust the darkening of the lens according to the ambient light. Completely automatically without battery and in a few hundredths of a second. Electra works like the human eye, only faster: it has an unlimited number of darkness gradations and is almost instantaneous. Electra E-Green Lens Ideal for sunny to moderately bad weather as well as changeable days. Adjusts to ambient light within hundredths of a second. FeaturesProtective cover includedSilicone with progressive texture on the inside of the elastic bandCylindrical lens50 mm elastic strapOptimised fitCompatible with safety helmetsMicrofibre bag included for protection and cleaningField of view: 215° horizontal, 5.41 steradian fixedHypoallergenic triple density foamAnti-fog double lensAnti-fog treatment (standard 8 sec.): 77 sec.