The 3680-300 from Holland Shielding Systems is a Microwave Absorber with Absorption 25 to 50 dB, Frequency 30 MHz to 100 GHz, Power 3 kW, Thickness 11.81 Inch/300 mm, Thickness 11.81 Inch. Tags: Pyramid, Power Absorber, Hollow Absorber. More details for 3680-300 can be seen below.