This is Dexter's Stunt Knife Set. The set includes a retractable knife, two rubber stunts, and handle only variant that was used with the included chest plates. The retractable knife features a thicker handle so the blade would have room to retract and help with the illusion. When his hand was on the handle you wouldn't be able to notice that it was thicker. The chest plates were used to allow the handle to stay in place on the actors chest. I acquired this directly from a production member who worked on the entire run of the series.
