Trek Commuter Pro RT Front Bike LightA do it all front light that's powerful enough for off road riding. Kindbeam keeps more light on the trail ahead of you while avoiding oncoming rider's eyes, for a bright light that won't blind other trail users. A visible fuel gauge, wireless connection to tail light, and Charge back that works as a battery bank for charging gadgets, round out an industry leading set of features and make this Trek's best front light option. Battery Li Ion 21700 3.