Needs adapter-BA Headphones (Glover Park)

Headphones from BA 1st Class flight. Husband took them without realizing they can't be used without an adapter. See photo - two pronged connector, one is a 3.5mm headphone jack, and you can *just* plug that prong in and hear sound. The other prong is smaller, possibly for a microphone port, but the headphones don't have a mic, so your mileage may vary on this.
Easy porch pickup in Glover Park.