Cafec has taken a scientific approach to developing their filter paper and have used that same methodology to developed their optimal V-shaped dripper. Cafec has created a dripper with pockets on the inner surface of the dripper which help keep air between the paper and dripper.
These Flower Drippers are made of Tritan, a type of plastic which is tough, heat & chemical resistant, BPA free and highly transparent.
Available in 1 cup and 2-4 cup sizes (01 & 02 if you think in Hario sizing).
1 cup is here: https://ildogbonner.no/cafec-tritantm-flower-dripper-1-cup
And CAFEC Abaca filters for the 2-4 cup are here: https://ildogbonner.no/cafec-abaca-paper-filters-4-cuphario-02-100pcs