Simple adapter to attach to air compressors to assist with the inflation of air mattresses. 

One end fits a standard clip-on tyre inflator outlet, and the other in conical to jam inside the large inlets on an air mattress.  The friction fit between the rubber and plastic holds in place well, allowing for hands free inflation. 

I typically print a few of these and if they break, they break.  Suggest PETG or ABS if you will be out in the sun or leaving these in the car, but PLA works fine too. 

I usually print large side down, and I use a brim to help with the small contact patch.