The round nib allows ink to be stored by attaching a dedicated reservoir.
This means that the writing distance of the round tip is far more (usually about 3 times more than a round pen).
Sunlight nib.
Features/Tank Master is a new type of tip with incredible writing distance.
The ink is stored in the dedicated reservoir, so you can write more than 3 times more than a traditional nib with just one ink applied.
The number of ink is greatly reduced so you can improve your work efficiency.
Recommended for those who draw a lot of backgrounds and effects at once.
Applications / Cartoon characters (especially great for details, such as face, eyes, hair, etc.), effect lines, background
These uses are for reference only, so please use different uses according to the style of your painting or other addictions.
(From Amazon.co.jp)