Product review (2 stars): Nice design, cheap
The design is neat.  But they are very cheap quality...you get what you pay for I suppose!  Mine have little dents in them and I've only had them for a month or so. They are very flimsy as well. Also, you have to wait until the burners are completely cooled off before putting them back on top of a burner.  I don't think they were meant to withstand any heat.  Mine are slightly brown underneath probably from covering a burner before it was completely cooled.