HyperLight High performance LED Lighting. When wearing this high-intensity lighted waistband you will be clearly visible from over a half mile away. The light weight and comfortable design make them great for rollerblading, biking, running, team sports, or walking. The light can be either flashing or constant. The belt adjusts to fit up to a 36 inch waist. In addition to being a great safety product, it can also be worn as a fun novelty to attract attention at a dance, skating rink, concert or other night time activity. Safe, shock resistant materials. Lightweight (4 oz), comfortable design. Battery (CR 2032) included, over 100 hours of battery life.