airpods or generic headphone classic silicone case holder. it adapts to almost all models of silicone case, being able to hook it into the hole provided for the rear-camera.a point of glue can be useful to facilitate the grip of the headphones when needed, but it is not necessary especially if you want to test its effectiveness first without staining the cover.great for those who use the headset to answer the phone. but in almost all houses two can be inserted side by side for both aipods.print with 100% filling to reinforce the sealing tongue. I print them in petg which seems to me more robust but depending on the direction of printing you can also try them with Pla. I haven't tried with TPU having finished it, but I think it might be a good idea.the solution may also be fine for other types of headphones but I do not have the diameter measurements available (the length is always similar to the airpods and is irrelevant in most cases). However, I attach the fusion360 file for any changes