Perfume Studio 5 ml Clear Glass Roll On Bottle with Metal Balls for Aromatherapy Essential Oils and Pure Perfumes. Use the Roller bottle for our premium Grade-A Oils. The small Rollerbotlles are of top quality and made to last. Practical Size and small enough to easily fit in your pocket and purse; great for travel.NOTE: If you?re using carrier oils that are high lubricants such as fractionated coconut oil or jojoba oil, we recommend testing them for at least 2-3 weeks to avoid the metal ball from popping out. These oils tend to act as a lubricant to metal and depending on the blend, may loosen the metal roller balls overtime. Additional Details ------------------------------ Product description: Perfume Studio 5 ml Clear Glass Roll On Bottle with Metal Balls for Aromatherapy Essential Oils and Pure Perfumes. Use the Roller bottle for our premium Grade-A Oils. The small Rollerbotlles are of top quality and made to last. Practical Size and small enough to easily fit in your pocket and purse; great for travel.