These Gold Metallic and White Rubber Bulb Glass Droppers are Great to replace or add to our Dram Sized Vials, in Clear, Amber Green and or Blue. these glass droppers are wonderful, and dispensing liquids drop by drop gives wonderful control, and measuring. A wonderful way to make your own oil blends and perfumes too! Serums, carrier oils, almost any liquid will work in these droppers. 13/425 thread cap. Screw on cap THESE ARE PREMIUM GLASS PIPETTE DROPPERS.