We have been looking thru our collection of older electronic and smart-ish stuff. Lynn found a black box that said "Amazon" on it and asked me what it was. I looked it over but didn't know.
There was a model number on it. Looking up the model number got nowhere. I have nearly 3400 Kindle books and we have many other purchases with that company so I thought looking thru orders would not be very useful.
I called their customer service. It begins with mechanical voices offering services and purposes you might have in mind but none of the choices seemed headed toward having them tell me what I had purchased. I find if I press "O" about 20 times, I will get to a voice that says "let me call a person." If they connect me to some young woman with a foreign accent, one with the energy to speak very quickly, I can only understand a random 19% of what she says. This time, I got a man! Once he understood my aim, he was obviously perplexed. I am confident that he doesn't get customers calling to ask what they bought. I thanked him and hung up.
I tried putting the model number in Google Search and there it was! The object I had and the picture matched. It is for connecting a smart speaker to a landline.