Based on this product's specifications, here are some alternatives and similar models
Filament detector sensor FlashForge Guider 3 Plus (MPN 20003422001)
Summary description:
Filament detector sensor designed for the FlashForge Guider 3 Plus (MPN 20003422001). This accessory monitors filament presence and flow to pause prints on filament runout or break events, helping prevent failed prints and material waste. Intended for use with the specified FlashForge model, it integrates into the printer’s filament path for reliable detection and smoother print continuity.