The OBS Engine RTA features 25mm diameter and 5.2ml larger e-liquid capacity that can last for a long time. Features Temperature Control design, this Engine RTA won’t be too hot when work at high temperature. The top side filling design makes it easier to fill the e-juice into the atomizer tube. Comes with top airflow design, easy to adjust, also can avoid the e-juice leaking. Features unique deck design, this OBS Engine RTA will guide the cotton adsorb the e-liquid easily. With all the amazing design, this OBS Engine RTA will bring you grate vaping experience!