Thank you for viewing! This is the GlowStarRigel GL, a super high-brightness glow-in-the-dark keychain. G stands for (Green glow) B stands for (Blue glow) G/B stands for (Green and Blue glow) S stands for (S size, body 11x39mm, glow core 5x30mm) L stands for (L size, body 12x50mm, glow core 8x36mm) X stands for (X size, body 14x50mm, glow core 10x35mm) These indicate the glow color and size. Features: High-brightness type: Visible for about 6-8 hours. Super high-brightness, ultra-high brightness, and maximum brightness types: Visible for about 10-12 hours. (Values published by the glow-in-the-dark material manufacturer) Total length: Approximately 10 cm (including chain length) Width: Approximately 1.2 cm Thickness: Approximately 4.5 mm How to use: This keychain is made with glow-in-the-dark material, assuming it will be exposed to a powerful LED light. Before use, such as during nighttime agricultural work, charge it by exposing it to a powerful LED light or car headlights. It doesn't glow much under fluorescent lights or UV lights. Caution: The glow-in-the-dark keychain will dim over time. It will become bright again when exposed to light. This is handmade, so the finish is not as perfect as commercially available products. There may be distortions, air bubbles, and warps. If you bend it excessively, it may break. It is made of resin to prevent damage to your property. Thank you for your understanding and consideration. Information about glow-in-the-dark products is also available in my profile. #GlowInTheDarkKeychain