WeePro Universal Light Sensitive Helmet Visor Insert - Shield Film Anti-glare - Standard/Dark (Photochromic(Dark))

Easy to put on, clean your visor, peel off the back, position and stick on the front, that simple. In low light, I would say this product is about 15-20% light gray tint, after about 30-60 seconds exposure to direct sunlight, it goes darker, a dark gray tint about 75-80%. No noticable optical distortion, no change in colours or contrast, just darker. Then, in low light it seems to take about 15-30 minutes to return to the 15-20% light gray tint again.The self-adhesive glue is round the edges so you cant cut this thing to fit odd shaped visors, so check your measurements before buying.I have no idea how long it will last, so, will report back if it shows signs of going down hill. For the first week of ownwership I am happy and tbh, at this price, if it lasts a year, I'll get another.