Life-changing oven liner!  Just throw it in there or cut it to size if need be.  Cuts with standard scissors.  When it gets dirty, wash it off with ease and put it back in!  NO MORE SCRUBBING OUT THE OVEN!  You can also use it in your toaster oven!  Measures 15.5" x 19.25"  MAKE SURE YOU DON'T COVER THE CIRCULATION HOLES!  Be sure to maintain space between the liner and the walls of the oven.   Obviously don't put it on top of a heating element. 

Some people cook right on it.  We are not sure if that is a good idea because it is a special type of plastic, but allegedly it's ok to cook directly on in place of parchment paper.