The Olight i2 and i3 are essentially the same light. The main difference between the two is the power source. The i2 is powered by one AA battery, and the i3 is powered by one AAA battery. Both lights have roughly the same output being only 5 lumens apart. The i2 maxes out at 75 lumens, and the i3 tops out at 70 lumens. The larger reflector of the i2 will give it more throw than its smaller counterpart, the i3. Both lights have enough power to illuminate objects at 100 feet out, which is amazing considering the size of these torches. With power like this available in keychain size there is no excuse not to carry a nice EDC light. Having bigger flashlights on you is great, but having something like the i2 or i3 on you at all times is pretty much invaluable.