Heh, I know this one. Those are
Kensington Macintosh II stands. They are not an Apple product and wouldn't have been bundled with a Mac II (unless the packing list states so - do you have the packing list?). These stands were made of metal and have little foam pads where the stands touch the Mac II, exactly like the one in your photo. Look up Kensington products in various Macworld magazines -- sometimes their ads or reseller ads listed them.
And yes
@jessenator my 3D printed Mac II stands are holding up well, though they're not in use currently, but safely in storage until I have room to permanently set up my IIfx again.
@hyperneogeo Besides the stands, what else was in your box? Can you show more photos? I know you've got the Japanese version of a IIfx, but I'd love to see photos of the packaging and included documents/accessories. I'm working on collating this info together in another thread:
Does anyone know exactly which manuals/accessories were packed with a IIfx? If anyone has a IIfx packing list, that would be helpful. I found these photos from someone who got a boxed/sealed IIfx but I don't have photos of everything. You can see a little pile of stuff there under the Thanks...
68kmla.org