CynKen 20pcs 2ml Graduated Plastic Cryovial Cryogenic Vial Tube Self Standing with Cap

I got these specifically because they clearly state they are polypropylene. I wanted to be able the use them in an autoclave without them melting. Keep in mind the size. These are small which is exactly what I wanted.

Bought these to hold small vials of oil, and the gasket is supposedly silicone and the container polycarbonate. Should work well and decent durability/seal.

PROS: I really like that they are available at all. I found out about these through lab work years prior, had a recent YouTube project and these were perfect for the project. My regular pill container that I had been using for Thyroxine had been invaded by the ants that get in my house. I knew that one of these would hold several days, but I needed a seven day container for thyroid medication that ants would not get into. It is not something normally done with these but I used HOT GLUE to glue seven of these together. I guess another PRO for these is that they did not melt when being hot glued together. I like that I now have an ant proof 7 day pill container. CONS: Price. I would have liked to get more like 50 or so for the price but was willing to accept the price given for twenty. Yes I'd buy them again if I need more and I'd recommend these to a friend.

The good news: They do actually have o-rings and provide a good seal. The o-rings are the same color as the plastic instead of black. I am using these for dip pen ink. The ink does not leak and the plastic is not being stained. Also, the inner diameter is just wide enough to fit my glass dip pens into, which lets me work with just 2ml of ink at a time instead of a whole bottle. Just perfect. The bad news: The white markings rub off easily so you will lose your label and graduations if you handle the tubes repeatedly. I am opening and closing the same tubes repeatedly so the graduations started wearing off right away.

We needed some very small containers with screw top lids and these were perfect. We love that the lid seals so it will keep the log inside dry. They are small enough to use exactly where we wanted to. We also like that they aren't flimsy and seem like they will hold up.