The MR11-0039-20 from MAST Technologies is a Microwave Absorber with Frequency 30.0 GHz, Thickness 0.038 Inch/0.97 mm, Thickness 0.038 Inch, Thickness (mm) 0.97 mm, Operating Temperature -60 Degrees F to 375 Degrees F. Tags: Tuned Frequency Absorber. More details for MR11-0039-20 can be seen below.