Everyone knows zippers and uses them every day.

The perfect pair

The difference with Kumja adapters is that we combine two zipper halves that don’t actually belong together! Zippers are manufactured as a unit of two halves, allowing them to connect perfectly. It’s extremely rare for this perfect pair to be separated and paired with other counterparts — with Kumja this is exactly what happens.

There are no official zipper standards

There are countless zipper manufacturers. At first glance, zippers of the same type and size look identical. Often they do fit together because there are inofficial standards. However, there is no official norm, and the detailed design can vary from slightly to extremely different depending on the producer.

The jacket brand doesn’t always help

Additionally, the manufacturer of your zipper is often unknown. Jacket brands usually “brand” the zippers by printing or embossing their own name on them. But the zipper itself is a purchased component from a zipper supplier. Incidentally, different zippers can sometimes be found within the very same jacket model.

Production variations in zipper manufacturing

To complicate matters, even if we know the zipper brand, it doesn’t automatically mean it will fit, because different batches may vary due to production fluctuations (longer/shorter pin, thicker/thinner teeth, smaller/larger tooth spacing, …). Coil zippers in particular are prone to relatively large process-related variations.
As described, this usually doesn’t matter at all, because in 99.99% of cases zippers only need to function as their original pair.

Puzzling for a good cause

To keep belly & baby warm, we’ve become true zipper experts and are solving a high-level puzzle here.
We stock the same type of zipper from several different manufacturers, for example. And we apply all possible tricks and modifications to ensure that an adapter works with as many potential “counterparts” — i.e., jacket zippers — as possible.
The success rate is therefore very high.

Doesn’t fit = bad service or bad product?

Why are we explaining all this?
Very few customers are aware of these technical details. Sometimes, a non-fitting adapter is equated with bad service or poor quality. We always do our best to find a solution. Only in rare cases does a solution simply not exist. In those moments (and not only then) you have a full right of return — even if the adapter was modified based on our advice and we can no longer use it.

Your order is therefore completely risk-free.

The more information, the better it will fit

Please provide all the zipper information we request as accurately as possible. This helps us identify the correct adapter and avoids back-and-forth shipping if it doesn’t fit because information was missing or accidentally incorrect. We cover the costs, but it still means waiting time and extra effort for you.