SMELL-PROOF and AIRTIGHT- Heavy durable ultraviolet glass blocks air exchange and locks in aroma. Premium UltraViolet Glass (UV-A) protects against harmful light. Storage containers perfect for storing perfumes, colognes, tinctures, essential oils and any other liquid requiring precise measurement and protect your liquid potency for up to 2 + years. The matching dropper assemblies are available in multiple closure styles and are equipped with the DripTrap bulb, which eliminates leaking. There is also an option for graduated pipettes, perfect for accurate dosing.