Here is what's new with MKIII: Reverse clicky switch is back Thinner tailcap allows more room for your finger, making the button easier to operate Better fitting CNC machined pocket clip has almost no gap between the body and the clip, and tailstanding is improved (smooth body still has a small gap since it's slimmer than frag). Anodized titanium screws New titanium washer with a keyring loop. comes with a split ring (if you need plain washer without the loop, see the link below description) Bigger inner diameter to support 10440 USB-C batteries Compact size together with a proper pocket clip makes it effortless to carry around. Click switch with a simple UI makes it easy to use in different situations. Quality build and good materials ensure longevity, and all this without breaking the bank. The light source is a Nichia 519a R9080 4000K LED. The light ships with a 350mAh rechargeable 10440 battery. Compact EDC torch Reverse clicky switch Milled titanium pocket clip Ti anodized screws Comes with the loop washer and split ring