Perfume Studio Set of White Frosted Roll Ons with Black Caps. 10.5 ml - 5 Units. Includes 5 interchangeable plastic and 5 metal ball roller tops to use depending on your application. IMPORTANT: Only use the metal balls with pure uncut essential or perfume oils. If your oils are blended with any carrier oils such as coconut, jojoba, almond, etc., the metal ball will pop out of the housing. For these blends and type of lubricant oils, use the plastic balls instead. If the metal ball pops out, then you're using a blend that contains these lubricant type oils. METAL BALLS ARE ONLY FOR 100% PURE, UNCUT OILS. GUARANTEED AGAINST LEAKS. These Perfume Studio essential oil Roll ons have been factory and field tested for leaks with pure, uncut essential oils. Additional Details ------------------------------ Warranty: 90-day guaranteed against leaks/defects. These perfume studio essential oil roll ons have been factory and field tested for leaks. If you encounter any leak problems or defects with these metal roller balls within 90 days of purchase, you may contact us for a free replacement/refund on your purchase.