Small 3ml glass vials with a rubber base for adjusting capacity or to act as a plunger. These are suitable for craft projects and whilst they are sterilised with care in an autoclave, the sterility has not otherwise been tested and cannot be guaranteed. During the sterilisation process, the plunger may become pressed into the vial some amount, to extract it, you can use a syringe with a small gauge needle to push air through the top until it pops out, this can come out fast so make sure you have something clean to catch it in!