Primary Lens inside has mottling.

[PKay]

Sky Watcher 150ED Super APO.
The scope being a refractor is fully sealed, that's why I bought it.

Whilst cleaning the outside of the primary, the sun was at just the right angle,
and I could see mottling on the inside of the lens.

Looks like moisture has condensed and then dried.

Can I pull out the lens?
I thought the scope might be nitrogen filled, but obviously not.

[MortonH]

The scope is 'sealed' but it's not an airtight seal so moisture will get in any time you use it. If it's dried moisture you're seeing then it's possibly best to leave it alone but if it might be the start of mould then it needs attention. If it's on the rear element nearest the focuser you could remove the lens (don't ask me how to do this!) but if it's between the elements the whole lens assembly would need to be taken apart, which is much more complicated and usually requires expert knowledge to get it back together and collimated.

Good luck. Hopefully others will chime on with more useful information.