OnAxisLock adapter for AIRY 72/80/90 OTAs

OnAxisLock is the accessories locking system that, compared to those using normal screw, offers a greater clamping force, avoiding any possible flexure (so it's perfect for astrophotography), it does not damage the connected accessory and it perfectly keeps the optical axis of the telescope.

All this thanks to a new locking device with double ring: just rotate manually the appropriate outer ring (designed to allow an easy grip, even with gloves) and you will get a perfect closure!