I use ATH-M50x headphones for live mixing, and M40x for tracking/monitoring for location recording. They come with 3 leads, but only one of these adapters. You have to use a threaded type or they won't correctly attach, and if you lose it (which I often do) the only way AT supplies replacements is with a whole set of 3 new leads, with only one adapter again.
I ordered this to try it out and found it was identical to the AT adapter - they probably come from the same factory. So, next time I order from Thomann I will buy at least 5 more, so every lead I have for both headphones will have an adapter at last!