Make your own inline filament diameter sensor (under $5)! - YouTube
GitHub - Deutherius/Filament-Width-Comp-Experiments: A couple of results from filament width compensation using a single mechanical/hall-effect based sensor
Objects with Intelligence Web Store - Objects with Intelligence, LLC
3DPrinter Filament Diameter Width Sensor Assembled from JasonKits on Tindie
Prevent Failed Prints With A Filament Speed Sensor | Hackaday
Precise filament sensor optical width, move and runout - Development - OctoPrint Community Forum
The Sensor project - Adding Telemetry to a TAZ - Hardware - LulzBot
Filament Width Sensor Prototype Version 3 by flipper - Thingiverse