It's a simple, yet clever concept: if there's too much water building up on the surface of the cover, just drain it all away ... of your truck's bed from the outside world. Thanks to the rubber ...

Screw-on cover: Visible screws that you just have to unscrew. Snap-in cover: Attached to the drain hole with small clips.

The patent-pending invention provides an effective cover for the drain on an in-ground pool. In doing so, it prevents worms and other matter from accumulating around and over the drain.