Leica M rear lens cap (Generic) brand_Paul C Buff with smooth focusing and good

with smooth focusing and good diaphragm action

The Nikon 24-120mm f4 G AF-S VR Nikkor lens is a full-frame autofocus zoom lens for film or digital SLR cameras

but this is a good "user" example if you don't mind the aforementioned quirks

This is a tiny leather case for a Nippon Kogaku viewfinder (not included)

but they wind into a proprietary Robot cartridge (included) as you shoot

Leica M rear lens cap (Generic) brand_Paul C Buff with smooth focusing and goodGeneric rear lens caps for Leica M mount lenses, for anyone who's looking for a cap and doesn't care if it says "Leica" on it. Image is for illustrative purposes. Item may differ slightly.