The MR11-0013-20 from MAST Technologies is a Microwave Absorber with Frequency 13.0 GHz, Thickness 0.051 Inch/1.3 mm, Thickness 0.051 Inch, Thickness (mm) 1.3 mm, Operating Temperature -60 Degrees F to 375 Degrees F. Tags: Tuned Frequency Absorber. More details for MR11-0013-20 can be seen below.