For your safety, you want to be seen while doing your running routines at night. The improved second generation Saucony USB LED Light is the right light source for you. It will keep you visible from up to 100 yards away (individual results may vary). In addition, 1 hour of charge will give you a minimum 1 hour of flashing light. The LED light lasts up to 100,000 hours of service. It is USB rechargeble and there is no need for batteries, ever!