1/8" x 1-1/2" x 3-1/2" Plastic Shims Structural Horseshoe U Shaped, Made in USA, Tile Spacers, Blue, Qty 100 by Bridge Fasteners

they are what I recommend when I have to shim the special doors I install. they are tuff and I won't have to worry about them failing

Great product. Stand up or lay down for grout joint. Easy clean up.

Product worked perfectly for shimming the elevator I was fixing.

Great for remodeling. I recommend getting a couple different thicknesses.

worked great for my purpose.