5ml Glass Syringes with Caps for Laboratory （10Pack)

They aren't airtight. Apparently, that's not a bad thing - there's a compound, "Dow Corning high vacuum grease" that makes the syringes more airtight.So, they are not *badly designed*, okay? They are supposed to be glass-not-plastic, and thus, not supposed to have a silicone or plastic plunger, that creates an airtight seal. Instead, that grease, above, applied about halfway up the glass plunger, will allow you to draw an airtight bolus (dose) of what you need. In my case, I need to use these for tinctures, made with alcohol, which is even less easily drawn-in than water.Now: *IF* the product information said "these aren't airtight, and shouldn't be, unless you apply a vacuum grease..." I'd have given 4 stars. But I couldn't go as far as 5 stars, because, dangnabbit, it didn't work for the obvious purpose for which I bought it.

Apply a very slight ring of “Dow Corning high vacuum grease” just below halfway on the plunger and it won’t slide and leak contents on its own, and thicker fluids can be picked up and dispensed. It’s a game changer.

Also, these syringes do not seal well and are basically useless.

I have used a lot of all glass syringes over the years. These work well and the price is right. All glass syringes are not air tight; they are not intended for that purpose. They are great for solvents that are incompatible with plastic or rubber plunger syringes.

If I could have given them zero stars, I would have. Opening the box you see that the markings on these are very pale, looks darker in photo,) some worse than others, and leads you to wonder if it will rub off soon. In using them, you find that you have to hold the plunger in place or all the liquid just runs back out of the syringe. Inconvenient, awkward, and it wastes product.

These are pure glass with no rubber attached to the plunger. Light sera fill the syringe fine. However, when a heavier sera is introduced, they fail to fill or dispense correctly. My primary use for them is, of course, the latter.

The tolerances between the tubes and the plungers is super liberal. Can hardly even draw up water let alone hold it. They look pretty cool but are essentially non functional.

Licking

Pretty much useless

Great product but very breakable. Caution advised.