Amazon.com: Official Creality 3D Printer Parts Filament Detection Module Detector Sensor Switch Run Out Pause Monitor for Creality Ender 3 V2/CR-10 V2/V3 /Ender 3 Max : Industrial & Scientific
EZOut Filament Sensor Kit for Ender 3/3Pro - V1.1.X Board - TH3D Studio LLC
Reuse Ender 3 CR10 Z End Stop into Filament Runout Sensor - Print 3D World