Product review (4 stars): make sure to install this concave side up
I originally installed this convex side up following another reviewer's picture because the package did not come with installation instructions or a diagram.  This prevented the food from falling through the hole. But once I reinstalled it convex side up, it does what it's supposed to, pretty close to the original.  The only difference is the new rubber sits higher and is stiffer.  I took off one star for lack of installation instructions or picture of final look which would have saved me some time.