SwitchBack Designed to be used in conjunction with a handgun. You can put your index finger through the ring and press the protruding part of the ring with your thumb, which will push the tail switch with the back of your middle finger, allowing you to turn the light on while holding the pistol. In addition, rotating the ring on your index finger allows you to quickly switch to thumb-activated switching. With this product, the part where the light passes through has been cut diagonally and enlarged, making it easier to open and close the tail cap than the conventional straight type. In addition, the pocket clip has a return, making it possible to attach it to PALS webbing, and the connection part of the ring can be opened, allowing it to be attached to belt loops, etc. Inner diameter of light mounting part: Approx. 2.6cm Inner diameter of finger ring: Approx. 3cm Clip compatible width: Approx. 3.3cm *The inner diameter of the light mounting part is a rough measurement, so if you are unsure, please ask for details. Thank you for viewing.