[LewisM]

In my box of odds and sods I recently got from the USA - call it an astro lucky dip - was a Tak step-down adapter.

Now, the odd bit is the telescope side is dual threaded - larger thread in 60mm (same as Vixen standard, and fits Vixen precisely), the smaller thread is 53.5mm or thereabouts.

The other side has what I THOUGHT would be a standard T thread, but it is not - it's a 47.5mm thread.

The edge reeding is IDENTICAL to all the Tak adapters I have, and it just LOOKS Tak. It does not look like any Vixen adapter I have or have owned before, though as I said, it has the 60mm Vixen standard thread.

Did Tak use a 60mm/53.5mm drawtube thread ever? If not Tak, which manufacturer perhaps?

I have NOTHING that threads onto the "camera" side, but as I said, it threads onto my Vixen drawtubes just fine.