These lanyard is a perfect light when you Walking the dog, Cruise, Darkness setting, Evening party activity and other outside sport at night, you can use it to alert the security through the shine. You also can use it for hold your any ID Card and keychain. Whenever day or night can be used. This LED acrylic holder can hold up to 5 credit card size ID cards, which is easy to scan, and it can save your name card, key, money or transportation pass safe and dry.. Turn them on at night they will make it easy to find each other in the crowd. TPU material Super Bright Rope + ABS Touch Control Switch Box + Removable Battery. The batteries are replaceable, comfortable and stylish enough that the teens, kids and adults will wear them too. Made of Nylon, it is really durable.