Especially disappointment: the headphone portion runs natively on Mac but the micro part is not working. Indeed, the line-out jack on the back of my Mac Pro 2010 requires an amplified microphone. Two solutions:
1- buy an adapter 3.5mm IN + OUT 3.5mm to 3.5mm male 4 segments (type "headset") and plug it into the jack "headset" Mac. There are two incompatible standards and in general the user feedback are very mixed ...
2- buy an adapter 3.5mm 3.5mm IN + OUT to USB (look for "External USB sound card"). Sennheiser UUSB 1 is lent me that works perfectly but is old and not found (ASIN B000Y9TQWK). I just ordered an external sound card "Creative Sound Blaster Play!" which I hope will give me satisfaction, but that adds more than 20 euros to the price of the helmet :(