The goal of choosing the correct size is to make sure there is enough support to hold the lens in place, without making it so large that removal and replacement are difficult.

The most reliable measurement is of a currently installed panel as long as it fits securely in the frame and is not too tight.

Our lenses are sturdy enough to remain in place with as little as 1/4 inch support from the frame along the perimeter, however optimum overlap on the frame should be 3/8 to 1/2 inch in most cases. This means the lens will be 3/4 to 1 inch longer/wider than the light opening. Where more vertical space is available in the fixture, you may have up to 3/4" of perimeter support.

Note - If custom sizes are ordered, the artwork is resized so that no part of the image is cropped off.