Special only. Incorrectly sized Crystal Dragon flanges. They fit 4" ferrules perfectly with standard gaskets and clamps on one side, 4 holes for rods. The inner flanges are too small for our gaskets and glass at ~118mm in the recess.
May be perfectly suited to anyone building a 'glasser' if you can source suitably sized glass lenses and fashion your own gaskets.
These are sold per pair at under cost price, once gone they will (hopefully) not be restocked.