KALLORY 4pcs Rose Quartz Roller Balls for 10ml Essential Oil Bottles with 16mm Neck, Crystal Stones Roller Ball Inserts for Refillable Oil Diffuser Bottles

["Core Compatibility: Specifically designed to fit 16mm neck essential oil bottles these roller ball inserts provide a seamless replacement for your essential oils roller bottle ensuring easy portability and convenience during use","Even Application: an even and smooth distribution of essential oils these roller balls enhance the user experience by providing consistent coverage with every roll","Leakproof Seal: Equipped with a secure cap these essential oil bottle ball accessories prevent leakage maintaining the freshness and purity of your essential oils during storage and travel","Material: Crafted from robust materials resistant to breakage these stainless steel roller balls are reusable and ensure performance for your essential oil accessories","Easy Maintenance: Designed for simple operation and cleaning these roller ball inserts allow effortless refilling and upkeep of your essential oils roller bottle supporting daily use and hygiene"]