Simson Battery LED set Flexy, black has a flexible, lightweight housing. The universal silicone mounting strap ensures easy use on, for example, the seat post or on handlebars. The lights have an on, off and two flashing functions. The push button is easy to operate, even with gloves on or in the rain. The rubber mounting strap can be used for diameters up to 35 mm. The lights come with two CR2032 batteries. These are easy to replace when the batteries are dead.