Break or lose the little plastic piece that keeps the headband padding from sliding out of your Sennheiser headphones? Here's a replacement.
This fits my HD650s. They should fit the other headphones in Sennheiser's line that look similar. It's a tight fit, if your printer's dimensional accuracy is in question, well, expect to be sanding.
In the pictures, the black part is the (broken) original.
The author marked this model as their own original creation.