I never asked them explicitly that question, would be terrifically evil of them to have it set up like thatI can find it for sale but I can’t find any details on how it works or how to mount it. Also it seems like it may require the handset to work, do you know if it is independent?
But it did have its own buttons that responded independently so I’d say with like 90% confidence it’s standalone (no Handset needed)
I checked the Halcyon website and seems that it’s not out through them; but local shops here in EU (like linked above) have it in stock, I aslo saw people buy it already at Boot
Probably best to reach out to them and confirm the independent thing beforehand
Edit: re attachment to mask, IIRC it was using a „clamp“ that hold on to the edge of the mask lens (right at the silicone to glass boundary); there was also a joint to move it around (I think more range of motion than the SP, kinda like the Nerd)