David Clark Company Inc. Aviation Headset, Model H10-40 w/Mic Model M-4….In excellent to lightly used condition with just a couple tiny marks here and there….Everything is nice and clean....Carrying case also included….Made in Worcester, MA….Carrying case a tiny 1/4" hole on the back side of it….Pictures are part of the description....What you see is exactly what you get....I’m not a pilot and don’t know how to test these, so they are sold as-is…..All items are professionally packaged for safe and secure shipping....I’m sorry, but I do not sell on approval and there are no returns or refunds….Winning bidder pays shipping....I ship USPS only….Thank You.