The 18-400 Black Smooth Dropper Assembly features a precision 2.4375" glass pipette designed for accurate liquid dispensing. The smooth black closure provides a secure, reliable seal while the glass pipette ensures chemical compatibility and visibility of contents. Ideal for essential oils, tinctures, pharmaceuticals, and laboratory applications, this dropper assembly delivers consistent, controlled drops every time. The standard 18-400 threading fits most compatible bottles and containers, making it a versatile choice for your packaging needs.