The new M1 and M2 MacBook Air (and possibly other recent Apple devices) come with a 30W charger that does not provide a method for wrapping/storing the USB-C to USB-C or USB-C to Magsafe cable along with the charger brick. This slides onto the charger brick and has grooves for neatly wrapping the cable. The grooves hold onto the cable with a slight bit of pressure.
Print with ~30% infill and 3-4 perimeters for strength and to avoid gaps between the grooves.
Make sure you use a high quality filament or you may have issues with the grooves. Since this isn't a structural part that requires a lot of strength and weather resistance you can print it with standard PLA. I typically have the best results with Polymaker's PLA.
May 20th, 2023: added V2, updated model to have “grippier” teeth. Now the cable requires a slight bit of pressure to fit into each groove but the cable won't loosen by itself as easily as before.
The author marked this model as their own original creation.