This model is a set of headphones made using drivers harvested from broken beats solos. The driver housings are the correct size for replacement beats solo ear cups. I installed the speakers into the housings and the back covers onto the housings using hot glue. Be careful not to block the cut in the driver housing with hot glue as it will create too much pressure on the speaker membrane when the ear cups seal against your head. The strap simply snaps in place. I used a set of cheap earbuds to connect to the drivers. The strap should be printed in something like PETG for flexibility.
UPDATE: The headphone strap must be printed such that the layers go front to back on the model rather than vertically otherwise they are likely to separate as the strap flexes. To avoid the same problem on the sections of the strap that hold the ear cup I divided the model such that both sections of fragile geometry can be printed separately and in their optimal orientation and then attached together using adhesive.