For my tablesaw, I like to use a two-slot zero-clearance insert (ZCI) that will accommodate both a standard blade and a thin-kerf blade. As with any ZCI, it’s best to secure the rear end of the insert to prevent it from lifting. With a single-slot insert, a flat washer screwed to the underside at the rear will do the job. However, that won’t work when you rotate a ZCI like this to use the opposite slot.To solve the problem, I screwed a figure-8 tabletop fastener to each end of the insert. Now, depending on which blade I’m using, I rotate the rear fastener outward to catch the underside of the saw table and rotate the front fastener inward, out of the way of the slots.