Retro-tech is the story here: collars that require a wrench and hang on so tight that they bite into the bar. They're not recommended for your fancy new Eleiko bar, but if you've got plate-loaded dumbells or kettlebells, these collars work and the teeth you save might be your own. Electroless nickel-plated. Small size for exercise bars(1" or 1-1/16" bar); 1" in width. Comes with an IronMind wrench (even that's made in the USA, of course).
Sale collars have have some stray black marks.