Both yours and @Seadog look as if they are not the best made and the steel doesn't look too great either to be honest, it looks soft. It may just be the way they look in the pics though?
I got mine from the USA via eBay and they are HHiP branded.
Edit, was probably 10 years or more ago that I got mine so possible the quality has dropped since then.
I've got a piston type and vey occasionally when changing back and forth between holders there can be some lack of repeatability, meaning the bit can be a few thou above or below centre.
This isn't really a problem as I am aware of it, a quick wiggle cures it.
I would suggest that as the piston type is a simpler design than the wedge type, any manufacturing faults in cheap import ones will cause fewer problems.
For that reason unless you can afford an Aloris type wedge maybe go for a cheaper piston one.
Did think Id only need a couple holders. I now have 5, ordered 2 more as ebay gave me a code 20% off anything.
I need a flat/vice holder that I could use for drilling and possibly very light milling. Would save a lot of setup time compared to swapping the slide, as I dont have a drill press. Might take a couple hours to make, good idea?
Or time better spent putting a crude drill press together?