The Adapter is nothing but the mount that comes with the Zen ED82 30X eyepiece..is not a 1 1/4 adapter,but as Frank explained ,a bayonet with some specific threads on it. I am sure some eyepieces would fit,..famous GSO superwide 20mm and 14mm,Those You could remove the barrels,no elements inside the tube,I think they would work..,,The Vixen ZOOM can also have the barrel removed ,im pretty sure...
What I did is change the pitch of my adapter to take Nikon eyepieces and used the nikon 38X WA with excellent results...I just sold the eyepiece and got the New Swarovski 30X SW ,to give a try,and maybe look for Nikon Zoom to take advantage of the 22X-66X that this zoom would grant...a nice advantage of 6X over the Zen zoom,That by the way I havent used that Much
I think a 1 1/4 regular adapter can be made for the ZEN,but there is not much room to fit the barrel inside the bayonet inner diameter,If any..it would be a tight fit..
The bayonet assembly in the ZEN ,though,could be easilly changed and is only attached in place,in its watertight socket ,by a retainer ring..Modifying this socket the manufacturer could create a scope that can have the whole bayonet removed and changed for an accessory 1 1/4 compression mount..This way the scope can be transformed to a 1 1/4 making it more appealing to Astronomy Eyepieces owners...
I particulary prefer Swarovsky eyepieces(but wouldnt mind the accessory Kowa bayonet either!!!!!)