Shower Towel Rod Shelf

My apartment shower has a towel rod inside the shower! I don't use this for a towel, as it would get wet, but it's a perfect place to put shampoo and things... aside for that pesky gap! Some things (smaller bottles and such) just slip right through and fall down in the shower, so this model fits snugly onto the square towel rod and props up a shelf for these items instead! Sharing in case anyone has the same or similar towel rod situation :)