Rubber Steel Sheet for Magnetic Trays

Ferrous sheet is metal infused rubber sheet. It has an adhesive back and is magnetically receptive. It is not Magnetic. 
I recommend N52 strength neodymium magnets for the best pull strength. 

The Sheets come precut to fit the war-ganizer magnetic tray. (210mm x 135mm x 0.9mm). Use them in your trays or wherever you want magnetic adhesion.  Also available are A4 sized sheets. (210mm x 297mm x 0.9mm)