Ferroxfoil is a flexible sheet filled with EMI absorbing material. It's effective against electromagnetic waves in a broad frequency spectrum. It can be wrapped easily around any shape, which makes it applicable in a variety of applications. The absorptive material is a distributed magnetic material, available in several grades :

5F1 for high frequency, 5R1 for high resistivity, 5T1 for metal shielding in HF RFID transponder applications, 5W1 for wideband suppression.