Kuretake Zig Brush Writer - Bright Yellow
This calligraphy brush features acid-free, water-based-dye ink. The brush tip draws broad to fine lines easily, allowing users to create beautiful gradients.
To activate ink flow, make sure to unscrew the brush from the barrel and remove the yellow ring (shown in the photo). You can then screw the two parts back together and thus puncture the opening to the ink reservoir, which is already located in the barrel. Apply light pressure to the "push" labeled area, and you should be able to see ink flowing into the window near the tip.