Can anyone explain how diamond locating pins work like a pin and

Slot Pins for Inspection Jigs

Suitable when clamping a workpiece with threaded part and measuring its diameter with straight part CAD ：: 2D 3D

pink lottery ticket Choose from our selection of slotted pins in a wide range of styles and sizes In stock and ready to ship

pin and slot It is supposed to be a slot machine thing that has the led's hooked up to pins 2-4, pins 6-8, …