CROCS Crocs Jibbitz Accessories Glow-in-the-dark! Cute! Flowers! Set of 5 ◆ Removable accessories I attached these to my child's Crocs for about six months (worn about once a week). They were very happy because they glowed in the dark on dark roads! Currently, all the LEDs light up, but I don't know how much longer they will. ・They light up when vibrated. They turn off automatically after a while. ・Over time, the LED function may deteriorate or be lost. ・The battery cannot be replaced. ・The battery part is designed to prevent water from entering during normal use in rain or near water.