DIN 18 screw cap with tamper-evident seal and dropper insert

01 · WHAT DIN 18 IS

It is the neck thread, not the bottle size

DIN 18 is a neck standard: it fixes the diameter and thread pitch of the bottle's mouth. That means any bottle with a DIN 18 neck takes this closure, whether it holds 20, 30 or 50 ml — capacity plays no part in the fit. It is the same logic as twist-off lids: the neck decides, not the container. Before ordering quantity, check the reference of your bottles or measure the neck; if yours is another thread, this closure will not do however well the capacity matches.

02 · THE TWO THINGS IT DOES

Dose, and prove nobody has opened it

They are different jobs and worth keeping apart. The dropper insert fits inside the neck and turns the bottle into a dispenser: the liquid comes out drop by drop instead of in a rush, which is the difference between a repeatable dose and a sticky bottle. The tamper ring is attached to the cap and breaks the first time it is unscrewed: until then, whoever receives the bottle knows nobody has opened it. It is the same idea as the shrink band on a jar — it does not seal better, it proves it has not been opened. And like any tamper evidence, it works once: for product that is sold, a new cap.

03 · BEFORE YOU BUY

Sold singly, and it fits any bottle with a DIN 18 neck. If you are packing a product intended for consumption — a tincture, an extract, anything ingested — confirm the food-contact suitability of the closure with us before a production run: it is the datum you will be asked for, and we would rather give it to you in writing than assume it. For cosmetics and non-food derivatives that question does not arise.