Thank you to Appelboom for lending me this fountain pen
Discount code for 10% off your purchases, excluding Montblanc: friend
Note that I point at the blind cap in this video and call it the piston-turning knob. This pen has a Delta-style ratchet-piston, and the actual turning knob is covered by a blind cap – my apologies for misspeaking! Also, apparently the nib is gold (even though it is unmarked), which justifies the price more.