Product review (1 stars): Crumbled after three uses
Words can hardly express how disappointed I am with these oven guards.  I had the fabric ones, but they got kind of cruddy over time.  We thought these would be a great replacement.  They went on the rack edges with no trouble and they did take some of the heat away.  BUT after only three uses, the lower one started crumbling apart (and I swear I saw "smoke" at some point).  This was in a regular gas oven at about 375 degrees.  I am returning them and will try another brand.  Such a bummer.