Manual can openers are hand held devices used to open food cans by puncturing and cutting the lid. They typically consist of a rotating cutting wheel and a serrated edge that grips the lid, allowing users to turn the wheel to create a circular cut. Some designs include additional features like bottle openers or magnetized arms to lift the lid. These can openers are portable, require no power source, and are a common kitchen tool for households, camping, and emergencies. They offer a straightforward and reliable method to access the contents of canned foods without the need for electricity or batteries.