Advanced Light Transmittance Meter Window Tint 1997 Tested w Case Instructions Tested and working as shown. There is some signs of age in the battery bay and I recommend you do not store this item with the battery sitting idle. Questions and offers are always welcome. This device is everything you need to test your car’s window tint. In order to be within regulation in certain states, window tint cannot exceed a certain percentage of light passing through. Whether you are in the window tinting industry or just an average tint-checker, this is an excellent tool for anybody who has a question about their window’s tint.