Predicate device
The legally marketed device that a 510(k) submission compares itself against.
Every 510(k) names at least one. The predicate sets the benchmark for intended use and technological characteristics. Any differences have to be accounted for, with an explanation of why they raise no new questions of safety or effectiveness. Predicates were often cleared against earlier predicates, producing a Predicate Chain that runs back decades, sometimes to devices no longer on sale.