I bought a Logitech MX Master and was dismayed that there was no on-device storage for the Unifying Receiver. Ultimately, I purchased a zipper case for the mouse and decided to make a holder for the receiver.
This should be printed in TPU (or some other flexible filament). It grips fairly tightly and should not let the adapter fall out unintentionally.
Logitech_Receiver_Keyring.stl | 114.9KB | |
Logitech_Receiver_Keyring_v5.f3d | 151.7KB |