The MR31-0001-20 from MAST Technologies is a Microwave Absorber with Frequency 14 to 18 GHz, Thickness 0.020 Inch/0.5 mm, Thickness 0.020 Inch, Thickness (mm) 0.5 mm, Operating Temperature -60 Degrees F to 375 Degrees F. Tags: Surface Wave Absorber. More details for MR31-0001-20 can be seen below.