drain cover

This isn't exactly a drain cleaning question but it's the closest forum I could find. My basement walkout has a drain with a cover (approx 5" in diameter). I would like to replace this flat cover with a domed cover. Where might I get one and more importantly, how do I know if it would fit?

Got myself into a plumbing pickle, right at the first hurdle. We have a funky smell coming out the bath drain. Despite knowing little about plumbing, I figured removing the drain cover would be a good place to start, get a better view down into the P-Trap etc. But the screw just keeps spinning...

Hello, I need some help with my bathtub situation. I just bought this house, and I have never seen an overflow drain like this before.. I'm trying to use this adjustable overflow drain cover that i purchased to make the water deeper for when I take a bubble bath.. and I can't figure out how or...