I am giving these 4 stars because of the white foam on the sides of the inside of the back of the frame that you have to remove. Otherwise there is no way to access the tabs on the side that hold the frame. I assume these were used for packing purposes. Also, the opening is not 4x 6, it is more like 3.5 x 5.5. But I worked around that. Otherwise, these would have received 5 stars.