In most cases, the 'plug' part of any great butt plug is hypothetical. Sure, it plugs up your butt, but it's not an actual plug. Here's the exception! Fort Troff's Kum Keeper Grommet Butt Plug not only has a sexily stretching shape and a hollow center; but also a removable stopper...a literal plug.

Once it's in position (in your/their butt), the Kum Keeper maintains an open channel for lube, fingers, and toys. If you're playing with lube or other fluids, the silicone stopper will keep everything inside the Plug - pop it in when you want to cork it. Meanwhile, the chubby swell fills you up just right.