Hybrid Electronic Noise Cancellation with advanced feed-forward and feed-back technology provides best-in-class active noise reduction. Digital Signal Processing (DSP) ensures high-fidelity audio for superior communications and music listening. Bluetooth wireless technology provides seamless integration for connecting to cell phones, MP3, tablets or other smart devices. Stereo/mono switch ─ compatible with all aircraft audio panel configurations. M-55 electret microphone with enhanced noise cancelling. Rugged yet lightweight alloy headband and suspension system is adjustable for personalized fit. Low profile, Outlast fabric head pad with vented design absorbs excess heat to keep you cool and eliminates 'hot spots'. Over-the-ear, leatherette ear seals with slow recovery foam cradle the ears in comfort and provide a snug, secure seal. Compact, in-line control module with backlit, touch-key user interface controls. On/Off, Bluetooth wireless technology and volume control Control module powered by two (2) AA batteries for up to 50 hours of use. Collapsible, folding design for compact storage in David Clark headset bag (included)