The base layer (A) is the magnetic layer.  It comes in a roll.  It can be rolled out over any smooth, clean, dry sub floor (concrete or wood)

The top layer (B) is any flooring product containing ferrite powder. When the top layer (B) is placed on the base layer (A), they form a magnetic bond.

Or, more commonly, the receptive material (made from ferrite powder) is adhered to the flooring via cold-press at the end of the manufacturing process.  (carpet, broadloom, ceramic, porcelain, stone). 

The result is a tight magnetic bond between the subfloor and finished floor that is virtually weatherproof.  The magnetic subfloor acts as a sound barrier and even provides crack isolation protection for ceramic floors.