TipCap "I have the David Clark and Bose ANR headset. At present I am using the DC with my Bose as a spare. The final result in attenuation, IMHO, is similar. The Bose works harder but the passive noise reduction is superior on the DC. I think it is "horses for courses" as the end result is similar. The new Bose X has changed to AA batteries with an auto switch off if you forget to switch off your power. The DC doesnt have that, even though there is a switch in the control box. It isn't relevant to that headset. A standard fit. Hope this helps."
FYI, My DC-56-HXL has an auto off feature and has saved me a few times. To combat the battery problem, I just use the rechargable batteries with no problems and save a few dollars here and there.