Good, practical solution for Temple Audio Design pedalboards. It will prevent your pedal from sliding around, no velcro needed, and you can reuse it (use a hair dryer or a heat gun to heat the adhesive and it will come out).
Word of advice, put the plate on the pedalboard first, and press your pedal on top of it. This will guarantee that the pedal is straight, and is absolutely needed for pedals that need more than one plate.
Use this size for big pedals, like Strymon or Eventide.