I saw the same on the plettenberg website. And send them an email about propellers....

Plettenberg will sell a 21x13 and 22x12 folding prop....

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we can deliver you a prop from RASA. We have the 22/12" in stock
and we let produce the 21/13" at this time.
the popeller is like the APC-prop, but a folding prop CFK.

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Price is about 46 euro!