Purchased for punching holes in plastic lids of standard and wide mouth jars. It makes the right size holes to mount silicone gaskets to insert three-piece air valves for fermentation projects like kombucha and raw sauerkraut. It's much cheaper to buy lids, gaskets, and valves to assemble than to buy ready-made fermentation lid kits. I didn't want to buy an electric drill or a special bit. This tool cuts through tough plastic can ends with one or more hammer blows. I'm a bit concerned that the sharp edge of the tool might dull after not making too many holes. I'll update the info on how often it's used when it gets boring. I use it on sturdy plastic lids about 1/16 inch thick, like a large jar of peanut butter.