Another hack from the Xiaomi sub-brand
Kaco SKY Fountain ink pen
Price $ 9.98 per item (price for store fans). A choice of several body colors. The ink color is black as always.
Pen thickness 0.3-0.4mm.
The body of the handle is plastic. Pen material stainless steel.
I will probably order one too for my own interest.
For comparison, the price of GB for such pens is $ 20.08 for 1 piece, but for BG $ 14.99