Features: Industrial grade Lumistick glowsticks are 50% thicker and glow brighter and last longer than standard grade sticks. You'll know you are getting "Industrial Grade" 15mm thick sticks because they have a flat bottom and built-in hook or loop at the top. The smaller "standard" sticks are only 10mm thick and are rounded at both ends. One package of Industrial Grade 15mm sticks contains 10 individual sticks and 10 separate elastic strings so you can use them as pendant necklaces or tie them to things. Once they start glowing, LumiStick brand Premium glow light sticks will last you all night. They will glow super bright suitable for 8 - 12 hours. Then, they will start to fade out but may continue to emit some light suitable for up to 36 hours. Inside the glow light sticks are two chemicals that emit light or glow when they are mixed together. Inside the glow light sticks is a thin glass tube, when you bend it suitable for the first time, you break the inner glass tube. This mixes the two chemicals together. Just shake it up and presto -- it starts glowing like magic! They almost never break open, but if they do, the chemicals inside can be washed off skin and clothes with ordinary soap or detergent.includes:10 x Light sticks