I can buy localy a second hand 2024/2025 ncx 6.4 and moto 6.4. Is this compatible with my 430 red rdm and with a cyclops?

Greetings from Bart from the netherlands

I don't think so. I think the pulley on the NCX and Moto has 4 rollers, cyclops uses only 2.
Severne even has a special extension for 4 rollers.

www.severnesails.com/hardware/triple-extension/

Largest I've used the cyclops on is a 6.7 blade. You have to remove the pin on the block otherwise the loop won't fit.

Both the Moto and the NCX have four rollers in the sail, and hence they need three rollers in the extension. The designated RDM extension from Severne is labeled "Triple X".

Note that there is no "pin" to remove in these sails that would make them compatible with the Cyclops extension.

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SurferKris said..
Both the Moto and the NCX have four rollers in the sail, and hence they need three rollers in the extension. The designated RDM extension from Severne is labeled "Triple X".

Note that there is no "pin" to remove in these sails that would make them compatible with the Cyclops extension.

Aha, there's the difference