It did not work with Mitel phone as advertised.
Hi Michael, sorry to hear this accessory didn't work. The RD-1 is designed only to give you ring detection in the headset when there's an incoming call. It won't give the ability to answer/end calls away from the phone with your headset. Not sure if that's what you were looking for or not, but feel free to contact customer service at 1-800-683-5715 and we'll find a solution for you.
Excellent customer service -