This is a clearance item with very limited stock and is priced to sell, so act fast! Simply push the orifice reducer into the neck of the bottle for a friction fit seal, and screw on the cap to engage the tamper evident bead. The inner dropper is great for dispensing a single drop from a glass bottle. This cap is ideal for thinner and less viscous products like extracts, essential oils or tinctures and will seal any of our glass essential oils bottles that have an 18 DIN neck finish finish. This cap has been tested with over 100 different essential oils to ensure proper fit, no leakage and no degradation even with citrus based oils.