Why two miter slots?

Why two miter slots? miter slot runners INCLUDES: Jig Fixture Bars – Fits the standard 34” x 38” miter slot with 36 inches of length; FUNCTION: These precision milled bars allow you to build miter slot track 1 MAKE YOUR RUNNERS Start by making a runner to fit your tools' miter slots Standard miter slots are ¾” wide by ⅜” deep Try to get the

miter slot track Introducing the Miter Gauge Jig and Fixture Bar by An extra hole along the top is included

miter slot runners When I make runners for a jig, either using wood or some man made stuff , I rip them with a slight bevel on the edges,but not out But if yours do, you can rub the sides of your miter slots with a wide carpenter's pencil then slide the runners along the miter slots a few