20-Pack 20ml Glass Vials with Screw Caps - Small Vials for Essential Oil, and Specimen Samples - Clear Bottles with Lids...

Great price and size

Update: I ordered a bunch more of these vials again primarily for seed storage as I've gotten into collecting wild plant seeds now too. I also raise species of lepidoptera and currently have a couple of katydids as pets. I was running into an issue with some species of tree branch cuttings, the leaves would dry too quickly and my caterpillars, the young ones especially, were struggling to get enough food from them before they became too dry and tough for them to continue eating from them. I saw some YouTube videos where someone used specimen vials to keep their cuttings alive, I decided to try that with these and not only did it work, I also realized these containers seem to be infinitely more leak proof than before. Maybe they switched to a better seal? I realized the old ones did have one in the lid but I think it was too thin and hard to do much of anything, the new ones (if there are new ones) it seems like the bottle rim does sink into it and it seals now. Regardless I do highly recommend these now for a variety of uses. I will probably still also plumbers tape the treads just in case, but if you're not dealing with biological waste/decomposition I wouldn't worry about having to reinforce the seal, these work just fine as is. First off I'll say the claim by the listing/manufacturer that these are "leak proof" is false and I don't even know how you could say that they are with absolutely no type of seal, it is literally just a plastic cap and small glass bottle. That said, the first bottle I tried leaked as I thought it would, but two wraps around the treads with plumbers tape fixed it no problem. I'm just going to do that from now on. I think even if you had one that didn't leak, plastic contracts and expands depending on temperature so there is a possibility of it leaking later on unless you seal it properly. It was 74 cents for a roll for some peace of mind, just do it. The glass is good and clear, they are a good size for a relatively wide array of specimens, and the plastic cap means there will be no corrosion or evaporation of storage chemicals like you have with cork and metal. The glass is also relatively thick and good quality. I didn't have any break during shipping.

Vials are exactly as described, great seal and sharpie dries fast on the label

These are nice small jars for element sample storage.

I purchased these vials for use in creating a specimen collection of aquatic invertebrates. I teach a course of field stream macroinvertebrates to young budding scientists that focuses on the systems integration of aquatic life with the natural environment. These vials are exactly what I need to allow students to get up-and-personal with the invertebrates. Clear, right size, and perfect. Dr. John