The 3650-20-CF from Holland Shielding Systems is a Microwave Absorber with Absorption 10 to 20 dB, Frequency 1 to 18 GHz, Thickness 0.787 Inch/20 mm, Thickness 0.787 Inch, Thickness (mm) 20 mm. Tags: Foam Absorber. More details for 3650-20-CF can be seen below.