Bracelets that glow are a go! Did you know glow was the first to show how to market light up products at night? Nice! Non-toxic fun for everyone. Parties in the park break out some bracelets and give them a crack. Before you know it, you've got a glow in the dark rave with activated favors everywhere. Eight hours later make sure to dispose properly since these obviously don't use batteries. Glow Bracelets contain a non-toxic, glow-in-the-dark chemical that illuminates once activated. To activate, simply bend the bracelet until you hear it crack. This will release the chemical from within the glow bracelet and it will immediately start to GLOW! They will last approximately 6 - 8 hours once activated. Each Bracelet is 8 inches in length and attaches using the provided connectors. - Length: 8 in. , 20.32 cm. - Width: 0.2 in. , 0.5 cm.