Just google "constant tension hose clamp pliers" and you'll get all sorts of hits.
These used to be extremely expensive when they first became common, I think the first one I bought was nearly $100 at the time (late '80s). Now the same things sold under a wide variety of brands (many are just reboxed) can be had for $25 or less.
Mine are Mayhew brand, made in France, and they have held up good. I have had to rebuild the cable operated one twice over the years (they sell a kit), but as much as I use it I can hardly complain.
This is a slightly improved version of what I use:
https://www.amazon.com/Mayhew-28655...6HZ06R1Z0AQ&psc=1&refRID=AXP0XNWNE6HZ06R1Z0AQ
And like I said, the ONE piece alone was around $100, I think I paid close to $150 for the pair back in the late '80s. So the cost has come way down, I hope the quality is still there. No idea where the new ones are made.
Fortunately, VAG uses the best constant tension clamps available, which makes for a much easier time (with the proper tools of course). Lots of other brands use really cheap flimsy clamps that bend and distort or those ignorant locking type that are nearly impossible to UNlock going back together because they were made for fast assembly with the little holder tang that of course was thrown away when the car was assembled. Fords are the worst for those.