A 17ml dropper bottle of thinner specifically formulated by Vallejo to work with their acrylic paints. Colours from the Model Air and Game Air are pre-thinned to be airbrush-ready, but will sometimes need a little additional thinning depending on your airbrush set-up and the conditions on the day. This thinner can also be used to thin other Vallejo acrylic ranges to enable you to use them in your airbrush. The thinner also delays the drying of paint within your airbrush, to reduce clogging and make cleaning easier.