This is the heated pad intended for the seat back.
The heated pad for the seat back is phased out from Alfa and the only compatible solution is the pad from SAAB 900. This pad has the correct resistance of 0.8 Ohm and the correct shape for the Alfa 33 seat.
The original manufacturer is SCANDMEC, Sweden which is the original supplier for nearly all auto makes. The resistance for the seat base pad is 1.2 Ohms whereas the seat back pad is rated at 0.8 Ohms. The logic behind is that the seat base should emit more heat than the seat back as the passengers during winter have the thigh protected with just a pair of trousers as opposed to the back which is protected with the coat.