I think it used to be fit for saws with 3/4” miter slots, but i had the dreaded craftsman saws with 5/8” slots, so thats whats attached. It’s fine, you can change it out, as it’s only screwed, not glued. There is some wingnuts on the backside, that are attached to slotted bolts, which allows you to adjust the width of the keyhole. Unfortunately, i believe that key IS glued on there, but no obstacle that a woodworker cant replace with something that suits their situation and desires. There’s even beveled edges to the removable key plate(i know thats not the name of it, but…) to be able to replace when it gets obliterated with multiple passes. It’s a solid jig
Please leave your name and number and what day and time you’d like to pick it up at, and only then will i reply to you, as im bound to miss emails, which emails arent optimal for back-n-forth conversations. Thanks and have a great rest of your day!😃