Those are interesting brass clamps They seem pricey. Are they worth it?
I like them for some uses. They don’t have much clamping force, but making boxes with ¼” thick stock, I don’t need a ton of clamping force, and they work well for that. They’re fiddly to apply, and almost useless one-handed, though, so keep that in mind.
I have 6 inch and 12 inch ones. I wouldn’t mind getting some 3 or 4 inchers some day, because who has ENOUGH clamps?