This is app the equivalent of a pinning chart, but is much easier, requires absolutely no math, and gives you exactly the same information. It also saves you from having to make paper copies of the worksheet, so it saves you money, while being environment friendly.Anyway, this handy little app is for locksmiths and calculates the pin matrix (pinning) for an interchangeable core (IC or ic core) when given the pinning for the CK, MK, GM, GGM, and control. You can also change the stack, and pin factors if needed (this allows you to use A2, A3, and A4 systems).