Anti-Kickback Pawls

Anti-kickback pawls are small, spring-loaded, toothed fingers mounted just behind a table saw blade, usually as part of the riving knife or splitter assembly. They pivot freely to let a workpiece pass forward through the cut normally, but the teeth dig in and stop the wood if it starts moving backward -- exactly what happens in a kickback event, where a pinched or twisted workpiece is thrown violently back toward the operator.

They're a passive, mechanical backup to good technique (a properly set riving knife, correct fence and blade alignment, not standing directly in the kickback line) rather than a replacement for it -- pawls stop a kickback that's already starting to happen, they don't prevent the underlying causes.