This is a two part button that allows one to route headphone cords on the inside of ones coat, jacket or hoodie. The button portion is sewn onto the inside of the piece of clothing in a manner similar to sewing any normal button. The headphone cord is placed between the internal snapping mechanism and the dome enclosure portion of the print is snapped onto the button portion. Optimal routing should start with a button near the inside pocket where your phone or other audio device is housed (this is the audio jack end), continue upwards with a button at least every 12 inches, and a final button near the back of the nape of the neck (this is the headphone end). The print file includes four buttons, which should be enough for most routings. I routed my headphones with three buttons. The dome enslosure can be released by pinching the snap mechanism while pulling up on the dome enclosure. This allows the headphones to be removed for washing. I have washed my coat several times and the buttons have weathered the washing machine/dryer well. Depending on the plastic used for printing, your mileage may vary.