I've never seen one like that before and doing a Google image search doesn't bring anything up.

But yeah, you may need a screwdriver so you can get underneath it to pry it up.

This would be a better installation...easier to replace items and better lever on the shut off valve.

I, too, suspect that it's just a stiff lever arm, and that you should be able to get it moved with some firm, but gentle, prying. The off position is likely a 90 degree upward rotation.

HI, maybe spray some WD40 or BreakAway on it and let it soak overnight. It may not help but it won't hurt it.

Good Luck Wood

Kroil oil is expensive and really smelly but I used it on stuck valves it it worked great. Be sure to use it on both valves as they move together.

Thanks everyone. It was stuck and I was able to turn it eventually.