Why did I buy this lens? 1) Because it's thicker than the stock one supplied with my 100% Accuri goggles, thus the name "Plus". The stock lens is thin and flexible, about 0.8 mm thick, and doesn't feel like it will offer much protection against impacts. This lens is thicker and stiff, about 1.8 mm thick in the middle, tapering to 1.2 mm at the left and right sides. I wanted this lens for greater protection against road debris when riding my dual sport on streets and highways to the trails. 2) Because it's a shaded lens. The stock one is clear.How Dark Is It? This smoked lens is not as dark as the "dark smoke" visor I have on my Shoei RF-SR street helmet, but it still seems to work ok in bright sun. With head-on sun, it is not as effective, but it does cut down on glare. This appears to be the darkest shade available. Wish they offered a darker shade. The 100% website says the light transmission for this lens is 25%, but it sure doesn't fee like you're getting a 75% reduction in light.Similar Lens: I couldn't decide between this lens (-1- Silver Mirror Smoke) and the similar (-2- Silver FLASH Mirror Smoke), so I ordered both to try. I like -1- (this one) better because it's a more neutral shade of grey which doesn't change colors, while -2- gives a very slight warm tinge. Also, -2- appeared to have more glare with direct sunlight. The light reduction feels the same between the two.