Functional as advertised. - Thyrm SwitchBack Flashlight Ring

easy to install. recommended to visit manufacturer website to determine which model to select for your light or which light to purchase with which model if one doesn't have the light already. appears durable. watching related web videos is adequate to learn to use. if tailcap on light is set for intermittent illumination I suspect recoil from firearm would make it difficult to maintain enough pressure on the unit to keep light on so practice on recovery/recoil management will be essential.