We used a red zipper for the jacket extender in the past. However, it turned out to be a little too weak, as it broke occasionally. Heavy loads are put on jackets during pregnancy and with a baby in a carrier.
Since may 2014 we changed to a stronger zipper and to make it obvious we changed the color to green.
When you place an order with Kumja products, we may ask you if you have any item with a red zipper. If you want to combine products with red and green zippers (e.g. order a new zip adapter for an older Kumja model), you will need the red/green adapter.