That is a proprietary cable that came with the Samson microphone. It would have plugged into an adapter on the other end to connect it to a microphone transmitter. That is a 2.5 mm end with a screw on connector for the adapters. I'm running in to the same thing myself.
I decided to go with this one myself and make a direct connection to my mic transmitter.
(This is a 4 month old post. I hope someone finds it useful.)