The 4th generation Aurora A1 has a redesigned operating switch that was made of stainless steel, the inner construction was improved as well, so it brings a better experience for operating. It has a lockout mode to prevent turning on by accident in your pocket or bag, don't worry about this anymore. The high-output LED delivers a max output of 650 lumens with a max beam distance of 110 meters, it's for when you need more brightness to light up a large area. On the opposite, the high CRI (color rendering index) LED delivers less output (max 420 lumens) but with a higher CRI, at least 90CRI. It's 5000K color temperature warm white, eye-friendly, and see the object color closer to the natural.