This lightweight black mesh vest is made with 3M Scotchlite reflective material, and features two illuminated flexible polymer strips (front & back) that can be set to one of three modes: steady glow, flash, and off. The L.E.D.'s are bright, highly visible and have a life of 100,000 hours. Wearing this vest when youre heading out for a run or ride in the dark is a comfortable, effective way to ensure youll be highly, instantly visible to oncoming traffic. Universally sized with hook and loop sections conveniently located at the shoulder, the L.E.D. Sport Vest is easy to slip on and off. Power/mode buttons sit above the left shoulder, and elastic sections with hook and loop closure allow adjustment at the waist for a snug fit. Two long-lasting, easy-to-replace batteries are included.