These are 17ml dropper bottles compatible with Vallejo ones - ideal for putting your own mixes in. Although they are supplied by Vallejo, they are a very slightly different shape (although the same diameter) and may have red or white caps.  They also don't have the Vallejo logo stamped on the bottom; I understand that all these little differences are because Vallejo want to avoid confusion with bottles they've filled and labelled themselves with paint of known quality and specific colours.

Sold in sets of 6