u/MasterpieceFirm5553

I’m looking for a replacement black D1 refill for my Rotring pen. I cannot find the exact refill with the code 23.09 (see image) anywhere online, and I tried the Schmidt 635M and it was fine but I am not 100% satisfied.

I mainly like the extremely fine tip and smoothness of the original Rotring tips and the fine tips listed on other refills (~0.5mm I think) still don’t feel as sharp and smooth. Pleas could y’all suggest an alternative or where I could get the original refill? Much appreciated x