Product Description Cuttable and versatile, this 3mm thick foam is used between the PCB and plate to reduce hollow sound, rattle, and generally round out the sound profile of a keyboard. For those after thock, it's a popular choice. The 68% layout is for use with any keyboard this size or below. TKL (87 key) for anything TKL and below. For boards larger than TKL I recommend using TKL foam to start with as full size boards are known to be too quiet under the numpad when inserting 100% foams. Of course the TKL and Numpad foams can be combined if you decide to. You can trim them easily for precise fitment to other layouts. It’s perfect for boards that need a bit more clarity and warmth to the typing experience, or as a thocky upgrade. Specifications Material: LE‑20 PORON® urethane foam Manufacturer: Kelowna Thickness: 3mm Installation: Remember to add to the PCB before putting on the plate or screwing in stand offs if those are involved in the build.