20pcs/lot PD638B side silicon PIN photodiode infrared receiving photosensitive tube, wavelength 940nm billion light black
https://www.vogueparade.com/shopping/EN/150412/1/1005003420933103/20pcslot-pd638b-side-silicon-pin-photodiode-infrared-receiving-photosensitive-tube-wavelength-940nm-billion-light-black//