Glow in the dark door knob marking ring

Glow in the dark door knob marking ring

Glow in the Dark Door Knob Marking Ring. 2.5" inside diameter X 4.5" outside diameter. Self Adhesive semi-rigid material. Uses phosphorescent (glow in the dark) pigments based on Strontium Oxide Aluminate Chemistry. Up to ten times brighter than that of conventional glow in the dark pigments. Will glow for up to 33 hours after the light source goes out. These glow in the dark signs are being installed throughout the country to assist in emergency evacuations.