GenesisI got got mine on ebay from a seller in the states who is out of stock right now. Mine seems legit, it fits perfectly and all that, however I cant speak for the other sellers. Its a pretty simplistic tube but i would recommend getting it if you plan to walk around with the flashlight in your hand. I carry the flashlight in my hand when I walk my dog and it feels better to me with the tube. For EDC you probably don't need it, but it does extend the battery life. Its a nice option to have. Also, the magnetic holder doesn't work as well with the tube, it will only hold the light straight down but not to the sides or angles.