They work well and are priced accordingly. Compact. Strong grip. Recommended for grasping pipe sizes from 3/4 inch to 1 1/4 inches in diameter. Tips of clamp adapt to create nice a grip on flat object. Cheap enough that if you lose them you just buy another pack. I ordered 6 packs just because I'm always losing these things.
Generally I'll use binder clips to position and weight poster board down when I use it as a sweep but lately I've been using a velvet type material (velveteen it's called) and the binder clips don't have enough reach or depth to get around the supports so I bought these. They work very well for light weight applications. I have the larger cheaplights also, 4 1/2", that I use to keep muslin backdrops taut and they work very well that way. I did write a different review on them. Some reviewers are using the 3 3/4" to hold 10' x 20' backdrops and wonder why they fail. They're insane for doing that. First, let's look at the name of this product, Cheaplights, which easily equates to light duty. Duh! To hold large backdrops get some Pony clamps. I have a half dozen each of 1", 2" and 3" Pony clamps. They are far more expensive but they are heavy duty. Basically, use the correct tool for the job.