DetailsYou put four sections together and fit them over each corner of your mirror or painting. The picture here shows two of the four mirror packs used so you can see how they work. This style can overlap and accommodate a picture up to 40"x60". EACH PANEL IS 31 3/4X22 1/8X3 3/8". YOU WILL NEED TWO OR FOUR PANELS TO MAKE A BOX. FOUR PANELS NEEDED TO MAKE A 40"X60"