Speed-Shims make it easy to level and plumb any surface. Just open the layered shim block to the desired thickness (like a book) and then peel the extra away. Each block has an adhesive back to hold it in place until fastened. No more holding, stacking, or trimming. Made of an engineered wood fiber, each package contains (6) 1/2" thick layered shim blocks. Overall dimensions of each shim block is 3-1/4" x 1-1/4" x 1/2".