Its overall diameter is 25mm, so it'll fit all of your atomizers that are 25mm and below in diameter. Everything is packaged well in a zippered pouch, which is again seen with mechanical mods that cost double, even triple the DejaVu Mech's cost. This allow for further customization for not only the looks, but how the button feels when you vape with it. What's even better is that it includes both a spring and magnet, which not many mechs include at this price range. It also features a hybrid top cap, so only atomizers with protruding 510 pins can be used.However, due to this alongside its construction and gold plated contact, it makes for an excellent performer.