Our GLOW TAGS are engineered from the brightest and longest lasting Glow In The Dark materials, professional quality epoxy resin, and laser cut for precision. SIZE: 0.4" (10mm) wide, 1.4" (35mm) long, 0.125" (3.18mm) thick. Comes with a 4" stainless steel ball chain and connector. CHARGING: When exposed to sunlight (preferably), UV flashlight, LED light or a bright light source, your GLOW TAG will charge itself up and glow throughout the night for up to 12 hours. GREAT FOR CAMPING: Mark your tent, cooler, flashlight, backpack, shoes, jackets, or any other item you'd like to find easier in the dark. Attach to keys to find them easily in your purse, or bag. RECHARGEABLE AND REUSABLE: Requires no batteries and uses no chemicals like glow sticks that can spill or leak. Just charge up the GLOW TAGS using light again and again! Made right here in Houston, TX USA.