28 LED PB Power Array(TM) tail light 28 LED microchips make up the Grateful Red's PB Power Array(TM). Its dazzlingly bright and the three modes give you safety options for day and night time biking. Mount it to your seat post or rear rack with the included brackets. -PB power array and reflector provide visibility for up to 1 mile -Steady, Superflash, and Courtesy flash modes -Ultra-compact case is weatherproof, lightweight, and durable -Rear rack and seat post mounts included -Up to 150 hours of run time on 2 AAA batteries (included) -85 grams