I use a 123 tactical light from Four Sevens. It takes two rechargeable batteries and throws 360 lumens for over an hour. Light is mounted on a twofish mountm also from Four Sevens. You will need a charger. Light, two batteries and a charger will run about $100 but well worth the investment. I've since added another light for my MTB, additional batteries and single 123 Olight for my helmet. I like to see as well as be seen. Don't go cheap on the lights. It is easier to cry once instead of twice when you have to replace a cheap light.