cone material bracelet. When absorbs enough strong light before being put in the dark, it glows blue, green or red depending on the style of the glow power. The glow will last for hours and gradually weaken. But when reabsorbs the light , it glows again like original shows. It is the most favorcarabiner keychainable item for the night event. It looks so good in the dark reflecting the logo custom. Hope this can help you for the glow in dark silicone bracelets. A uv silicone bracelet can carabiner keychaintransfer its color darker under sunshine when absorbing uv light. It is not only with good looking appearance but also indicating the strength of the uv index. So some uv silicone bracelets made as the indication with the ruler of levels of index. Wearing on the wrist to avoid long time staying under strong uv. So what makes it uv transfer ? The answer is the UV phosphor which usd uv energy to open the sensitive molecular bond and make it jump from low energy to high energy level There will be a change from visible light to visible light, resulting in the changing color from light to dark. It become a uv silicone bracelet when the UV phosphor is put into the silicone mass and produce it a band. Silicone wristband is not only used as promotional gift, but also as a medical tool. Medical id bracelets is commonly used. It is a high quality silicone bracelets with the ID printed on. We can print bar code, QR code or unique serial number together with some detail of the medical institute. Usually the wristband width need at least 15mm so that the code is clear enough to be scaned. We you scan the code with a phone, the detail of patient name, disease, status will show up. It is a good help for doctor and patient to know the treatment. All the medical bracelets should made from 100% silicone which is harmless and eco friendly to avoid secondary injury to patients.