My RavelCo key is made from a fairly brittle plastic and over time the nub that the key ring goes through has broken, as the rest of my keys typically hang from the ravelco when inserted in my car. I made this sleeve to fit tightly over the ravelco with the broken key hole and printed it out of Bambulab TPU-95A, then with a lot of pressure once the previous key nub was basically completely broken off, shoved the ravelco into this. It took quite a bit of pressure. Printed with 100% infill and normal supports for the key hole area.