The 3640-96 from Holland Shielding Systems is a Microwave Absorber with Absorption 30 to 50 dB, Frequency 30 MHz to 110 GHz, Power 1.5 kW, Thickness 3.77 Inch/96 mm, Thickness 3.77 Inch. Tags: Ferrite, Pyramid, Foam Absorber. More details for 3640-96 can be seen below.