Orion wide (Losmandy) to narrow (Vixen) dovetail adaptor, identical to this one:
https://www.bintel.com.au/product/or...arrow-adapter/
No great mystery here - it allows you to attach scopes with a Vixen dovetail to a mount saddle that only has a wide Losmandy-style dovetail.
I used this on a Losmandy G11 mount for scopes that I swap between mounts, but have sold the mount, so it's surplus to requirements. Only used once or twice, so condition is excellent.
Cheapest price I've found online is AU$190.
Selling for $95 ono + postage.
John