The Contour Shims are a great accessory for the creation of breaks and elevation changes. Experiment with different breaks, hills, and holes. The Challenging Hole Reducers make the hole smaller to make sinking a putt just a little more difficult. To be placed under the putting green, the contour shims will allow you to make countless different breaks on your green. Make a left-to-right break, a right-to left break, the hole twice as deep, the hole smaller, and so much more. The possibilities are endless.  Specifications - 1 Double Depth Cup to use with all of your single-depth (1/2") shims - 18" Circle Shim (1/2" thick) with two different hole placement options to create different breaks into the hole - 12" Circle Shim (1/2" thick) - 6" Circle Shim (1/2" thick) - 3 long, snake-like shims - 6 Hole Reducers (comes with a single-depth and double-depth version of each) Circle "donut" Hole Reduction Insert Half Moon Hole Reduction Insert Small Crescent Hole Reduction Insert