The 20ML Clear Dropper Bottle with 18MM PP Knurling Dropper features a glass tube, silicon white rubber teat, and a wiper plug for smooth, controlled dispensing. The knurled dropper provides a secure grip, while the wiper plug ensures minimal leakage and a secure seal. This clear bottle allows easy visibility of contents, making it an ideal choice for essential oils, serums, and other cosmetic liquids.