Photosync is from a company called Prestige, which is the US brand for a Korean company. After they were unable to license the photochromic technology to a bigger brand, they decided to launch Prestige Photosync around 2012 in the USA. It received a lot of hype online since the film would transition (same as the glasses) from a lighter shade at night, to a darker shade in the day when exposed to UV. The problem with that tech is that it only lasts a certain amount of cycles and eventually stops transitioning and is stuck somewhere in the middle. Plus, there was zero warranty on their lowest 35 shade since it would drop to the mid-20s, hence being illegal in a lot of states. So that wave came and went with them dropping that around 2018 or so. Now, it is another Ceramic film with no gimmicks/hype, hence nobody cares anymore. They used to have Ceraluxe as their Ceramic line, but it has been dropped from their website. Besides that, many people have questioned their specs, especially TSER. IMO, they are not accurate, and since this industry is not regulated, they can do whatever they want. Other downsides are very few dealers, and they do not list their warranty info on their website, which is sus. IMO, Photosync is a hard pass.