I purchased a piece of Optix Acrylic Sheet .220 18 x 24 to replace my yellowing other piece, which cost around $22. You have to unscrew about 15 screws on my Dilling & Harris Max-Vend II vending machine to remove the old sheet. I used my Craftsman table saw that I fixed the other day to cut the sheet. I purchased a little too thick of a piece so .220 will fit but smaller would have been more like the original sheet. Also the measurements are 16 5/16 x . Now it looks great.