The LS20-290 from Withwave is a Microwave Absorber with Frequency DC to 10 GHz, Thickness 0.11 Inch/2.9 mm, Thickness 0.11 Inch, Thickness (mm) 2.9 mm, Resistance 1 x 10^6 Ohms. Tags: Cavity Resonance Absorber. More details for LS20-290 can be seen below.