DA40 quick disconnect (QD) of Plantronics is Compatible with Plantronics H-series headsets:
H141, H141N, H251, H251N, H51, H51N, H61, H61N, H261, HW261, HW261N, H261N, H51N, HW251, HW251N, H41, H41N, H81, H81N, H101, H101N, HW510, HW520, HW530, HW540, HW710, HW720, H91, H91N, H361,H361N, H351N, H171, H171N, HW301N