The Telex Airman ANR 500 provides excellent active noise reduction of up to 15dBs for a comfortable flight with reduced fatigue. Telex combined a symmetrical headband, with plush cushioning, and adjustable pivoting earcups for maximum comfort on your longest flights. For clear communication the Telex ANR 500 features stereo/ mono volume control; so, you can manage the sound level depending upon your own hearing needs. Additionally, the electret, noise-canceling microphone ensures that you come through clearly to the tower, your passengers or co-pilot. The Telex ANR 500 is FAA TSO approved.