Despite the poor quality of its easily fading paint, this clamp is highly commendable for its price. It is extremely stable with strong tightening power.

Very good for its price. Quite stable with good tightening force.
Its paint is bad and easily peels off, but even more expensive ones that I have suffer the same fate.
All these clamps are made of cast iron and they all rust, but this does not affect their use.
For me, they are very useful with a 3" (75mm) and 5" (125mm) opening. I also bought 2 in 8'', but they are huge and not suitable for my work.
I think this specific company produces them up to 10".