lumens, runtime, UI all aside is there any flashlight that can run on 2Xcr123a's/rcr123a's/1X18650/1XAA/1X14500. i know the different batterey sizes but i see some companies using a sleeve or spacer. i have never seen a light that can run on all of these batteries, does it exist? and if it doesnt is there a light that i can buy/built a spacer that will make this possible. i know its not practical but how freaking cool would this be ( or is). it would obviously need to be able to run from very low to very high voltages and need some kind of insert/spacer/spare tube. i know of the gerber omivore it can use a single cr123/AA/AAA. so theres got to be a way.