The SDK 15 from KITAGAWA INDUSTRIES America, Inc. is a Microwave Absorber with Frequency 100 KHz, Thickness 0.02, 0.04, 0.06, 0.08 Inch/0.5, 1, 1.5, 2 mm, Thickness 0.02, 0.04, 0.06, 0.08 Inch, Thickness (mm) 0.5, 1, 1.5, 2 mm, Magnetic Permiablitity 1200 u. Tags: Ferrite. More details for SDK 15 can be seen below.