Notch coils perform well. A bit tricky to wick, you want the tails to have the height and touch the juice wells from the tank above or this thing will dump all your juice over your mod. I recommend setting the airflow control ring and screwing down the RTA on your mod slowly. Once the cylin is on your mod tight, it is difficult to adjust the airflow. Great flavor! Very easy to fill! Base and top cap has notches making it easy to grip and take apart. Why doesn't every company do this?