Designed to fit over an induction hob to protect the glass from being scratched. 
Made by Bake-O-Glide. 590 x 520 mm.
 
I have one on my hob.  I am inveterate pan shaker and was concerned that I might damage my beautiful new induction hob! All induction pans still work perfectly, and it can be washed in soapy water and dried over the cast iron cooker.