Cylindrical inserts for silicone stopper molds

Inserts for specially designed molds for making silicone stoppers with holes (e.g., for glass tubes and funnels).
Insert diameters: 6, 7, 8, and 10 mm

The molds themselves:
Single molds https://www.thingiverse.com/thing:7338514
Stack of molds https://www.thingiverse.com/thing:7338633

All individual models related to molds (molds, inserts, clamps) are collected in a collection: https://www.thingiverse.com/B_Artificer/collections/44023694/things