3M Scotchlite Very High Gain Reflectors 3000X 106, 4 in x 4 in, 50 sheets per carton Boxed

Uses micro cube corner reflection with adhesive and liner. Brightest tape reflector works with polarized and laser lights.
Retroreflective materials, such as 3M Cube Corner Reflectors, are used in a variety of photoelectric systems. The interruption of a beam of light can be used to trigger an action, such as setting off an alarm, shutting down potentially hazardous machinery, or simply opening a door.