Yes, these devices work almost like a vice used for wood-work.
Made of plastic, they attach to the edge of the kitchen worktop.
They have an in-built wide clamp, into which a jar or can can be inserted.
The turnkey on the clamp can then be manually tightened, holding the jar or tin firmly in place.
An opener can then be used on the lid, with the body of the object held steady by the clamp.