Designed to fit onthe Aga runners, this is a really useful shelf - as a half size cold plain shelf for baking, to slide into the oven over a cake that is browning too fast, a cookie sheet, or simply to put a pie dish on.  I use mine all the time instead of the Aga grid shelf to put dshes and non-Aga tins on.
 
Made in England by Silverwood. 
 
Not dishwasher safe.