Cygolite Expilion 720 USB with Cygolite Hotshot 2-Watt USB Rechargeable Tail Light and Water Bottle Powerful 720 lumen output Cree XM-L2 LED Enhanced Cycling OpticsTM (ECO) widens your field of vision and increases your visual profile Water resistant design for all riding conditions 1:15 ~ 9 hr run time