The 3640-1000 from Holland Shielding Systems is a Microwave Absorber with Absorption 11 to 50 dB, Frequency 30 MHz to 110 GHz, Power 1.5 kW, Thickness 39.37 Inch/1000 mm, Thickness 39.37 Inch. Tags: Ferrite, Pyramid, Foam Absorber. More details for 3640-1000 can be seen below.