12x75mm Glass Test Tubes with Screw Caps, Black, Borosilicate Glass, (Pack of 10)

The 15ml (16mmx150mm) holds 20ml. This extra space may exist for all sizes, so just be aware of that, should you want the smallest size possible for what you want to hold. A secondary consideration is that the inward bend at the lip that allows the cap to align flush with the wall also prevents them from pouring out smoothly in controlled amounts like you can with a normal test tube. I pipette the volume I want out, and I recommend a bent-tip pipette for anyone wanting to pipette liquids out of these. One piece was chipped along the threading. Some of the lids sit a little crooked, but they all seem to seal liquid tight. Small debri of some kind was found in one tube. Otherwise they are perfectly fine and I will be buying again.

Great value. Came very quickly.

As described

The tops can be a blessing & a curse at the same time. They're great!

The capacity of the tubes is exactly 5mL, all the way to the very top of the tube, leaving no bubble to aid in mixing. Not a bad thing, just keep this in mind for your intended use.