- Design with front light - LED reflective vest with front light, supports two-level brightness adjustment illuminates the road ahead, and no longer has to worry about the danger of tripping when running at night. - USB charging - The LED reflective running vest has a built-in 650 mAh polymer lithium-ion battery. It only takes 1-2 hours to fully charge and can last about 4-6 hours. When the battery is low, the indicator light will flash red, and when it is fully charged, the indicator light will turn green. It can be easily connected to any charging device with a USB port, such as computers, mobile power supplies, laptops, etc. - High Visibility and Various Colors - True 360 degree illumination,Change between 6 super bright solid colors - Red, Blue, Purple, Pink, Green, and Orange AND 3 eye catching multicolor flashing modes, Our special illumination modes are based on visual science to give visibility to you and warning to motorists. Modes are easily selectable at the press of a button, easy to access if you're walking, running, playing ultimate frisbee, riding a horse, or even riding a motorcycle. - Lightweight and comfortable - If it’s for a short jog in the morning with the kids, walking your dogs in the evening, or an all night solo ride, at only 152 grams – you’ll forget you’re wearing it. Using High Quality Sports Mesh and elastic makes the Tracer360 Sweat Resistant, Chafe-free, comfy to wear. The slim, minimalist design ensures minimal fabric-to-body contact, less sweat-trapping, and helps it not interfere with your HRM (heart rate monitor.) - Adjustable and Non-slip - Unlike other chest strap which would affect the heart rate monitor or too tight (especially for female) . Our waist strap (fits for 23" to 40" inch waist line) is elastic, breathable and highly adjustable, it could fit over your t-shirt . The non-slip rubber strip on the back could prevent the fiber optics slipping from your shoulder when running, making your running more comfortable.