"Holds 30 vials" is the most common line on a case listing and the least useful, because it never says which vial. The two sizes most people keep are very different objects, and almost every mis-bought case comes down to that.
The two sizes
- 2 ml and 3 ml vials (often called 2R or 3 ml serum vials): about 16 mm across and 35 to 38 mm tall with the cap. Flip-off aluminium cap, rubber stopper. This is the size most cut-socket cases are made for.
- 10 ml vials: about 24 mm across and close to 50 mm tall with the cap. Wider, taller, heavier, and they do not stand in a socket cut for the small size.
Dimensions vary a little by maker, so a socket needs a millimetre or two of clearance. A socket that is tight on a 3 ml vial is a socket you will stop using.
What that means for a case
A case cut for 3 ml vials holds exactly zero 10 ml vials upright. A case cut for 10 ml vials holds 3 ml vials loosely, which is almost as bad as no case. If you have both sizes, you want either two cases or one case cut for both. The 26 Protocol Case is cut that way: upright sockets for the small vials and a flat bay where 10 ml vials lie down.
What that means for a cooler
The inside of the VialHaus Cold is 40 mm tall. Standard 3 ml vials stand upright under the lid, up to 28 of them. A 10 ml vial with its cap on is taller than the well, so it lies flat. The page says so; we would rather you knew before you ordered.
Caps and labels
Both sizes use the same kind of flip-off cap and the same rubber stopper, so the handling is identical. The label is the real difference: a 3 ml vial has about 30 mm of usable height for a label, which is why our label sheet is cut to that size, and why a date written on the cap is the one that survives.
Quick check before you buy any case
- Socket diameter, in millimetres, for each size you own.
- Inside height with the lid closed.
- Opaque shell, not clear.
- Somewhere for a label, or room on the vial for one.
If the listing does not say the socket size, it was not made for vials. Storage accessories only; nothing here is medical advice.