Perfume Studio Premium Grade Blue Cobalt Glass Bottles with Removable Fine Spray or Glass Dropper Tops and 10ml/.33oz Clear Roll On Bottle. The blue glass bottle holds 1 fluid oz. Multiple Applications: They are ideal for essential oil formulas, fragrances, cooking oils, hair solutions, beauty products, home made tanning oil, plant sprays, bathroom fresheners, and for many other soluble thin liquids. These cobalt blue glass bottles are durable, easy to wash and reusable.