SMOK Osub 40W mods firing bar is almost the same with H Priv, SMOK Quantum, and X-cube, which you may press the sidebar to fire it. However, this device is a bit sensitive and may fire accidentally. Its micro USB is hidden on its side panel and covered with a magnetic plate that you can easily take off. It has a 2-amp charging like you’d find in smartphones these days. That is the reason why charging SMOK Osub 40W can be done quickly, yet no pass-through feature. This only means that it can’t be used while charging. The 1350mAh battery comes with a mini box mod that does not last for a day, yet the same may be said for any particular vape mod in this size and class. The chassis of SMOK Osub 40W mod is crafted of zinc alloy and comes with a brush type finish that’s fingerprint magnet, which leaves almost greasy feel if the oil in your hand transfers to the device. At the top of SMOK Osub 40W, there is a 510 threading as well as adjustable pin. Its front side is engineered with OLED screen and 2 function buttons. OLED screen is small yet easy to read and clear. The function buttons are small and rounded that can be difficult to press, particularly to those who have big fingers, yet aside from that, it is pretty well-designed buttons.