The PA-1771T ANR headset is both lightweight and comfortable with a genuine sheepskin headpad and proprietary silicone gel ear seal which have 30% less weight than regular gel ear seals. The Auto on/off circuitry allows the PA-1771T to switch on ANR when plugged into the aircraft and switch off when unplugged. Also, this headset will automatically shutoff with the radio or avionics master switch is turned off. The PA-1771T provides a true stereo input jack for compatibility with music devices such as cellphones, satellite phones, CD or MP3 players, and iPods. The cellphone system is designed to work with modern smartphones that have a 3.5 mm (4-conductor) jack or older cellphones with a 2.5 mm jack. This PA-1771T ANR headset (EDMO# PA-1771T) has 0.25 inch and 0.206 GA plugs.