I got one of these (first ver before the ventholes). After only four days of use, the bottom button broke off the shaft as I was screwing the button lock. Turns out the plunger shaft is not metal, but cheap plastic wrapped in a thin sleeve of brass. In my four years of vaping, I have never seen a device break so easily, or have such a cheaply made primary component. The whole reason I ordered the telescope was because it was advertised as an all metal, completely mechanical device - in other words, it should be durable. Turns out that it is so fragile that operating its safetly lock is enough to break it. I am attaching a pic of the broken shaft/button. I repeat - the shaft is nothing more than a very thin piece of plastic, wrapped in an equally thin brass sleeve.