We supply pyramid absorbers made from carbon filled foam in lengths of 100 – 2500 [mm]. The length of the pyramid absorber is determined by the lowest frequency that needs to be attenuated by the material. A chamber requiring a stable NSA of ±4 [dB] over a frequency range of 30 – 1000 [MHz] requires pyramids of over 2000 [mm] length. When immunity tests are being performed from 80 [MHz] and up, 7500 [mm] pyramid absorbers will suffice. In the case of measurements starting from 1 [GHz] pyramidal absorbers of 200 – 300 [mm] length are being used.