I made my own with plexiglass
you could also try to find solid surface counter to color match but it would be heavier and probably more expensive
I made mine in 2 pieces to match the double sink... this way you can leave one side open and use the other side for counter space.
they plexiglass is slightly lower than the counter, but this helps to make sure any water that might get on the cover drains into the sink.
There is enough flex in the plexi that I didn't need to drill finger holes... just push down at the middle to grab the adjacent cover.