TOPWEL 24pcs 5 Ml Refillable Amber Glass Roller Bottles with Balls and Black Caps (24) Capacity: 5.0 milliliters Size: 16mm x 57 mm (0.63 x 2.2 in.) Roll on Bottles with Balls and Black Caps Perfect for storing perfume oils or other liquids Perfect for applying diluted essential oils and blends directly to the skin.