Thanks Wookie; I had a look, and both my 8" and 10" Sky newts have this feature. It's a pity Sky don't mention it in their manuals.
Incidentally, has anybody noticed that the Sky dovetail mounts for finderscopes are made back to front. The little flange that limits how far
the dovetail can go in is on the lower end, so that if the retaining knob
comes loose the finder falls to the ground. Celestron ones are at the upper end, so it doesn't matter if the knob comes loose.
regards raymo