ITEM NAME:20pcs photoresistor LDR CDS 5mm light-dependent resistor sensor gl5516 arduin SE.20PCS Photoresistor GL5516 LDR CDS 5mm Light-Dependent Resistor Sensor Arduino. Resistance Illumination: 2. Dark Resistance: 0.5 Mohm. Light Resistance (10 Lux): 5-10 Kohm.