This is a "Play Me" tape used in the final trap at the end of movie. The last trap was the "Glass Box" that "Strahm" (Scott Patterson) was suppose to get into, but instead he pushes "Hoffman" (Costas Mandylor) into it resulting in "Strahm's" death. FYI: The Glass Box was also seen in "Jigsaw's Lair" in Saw IV.Here's a close-up of the tape recorder in the "Glass Box". Look closely and the "Play Me" tape is inside of it.
