ITEM NAME:50PCS GL5537 LDR Photo Photoresistor Light Sensitive Resistor Optoresist.50 Pcs GL5537 photoresistor LDR photo light-dependent resistors. Model: GL5537. 50 Pcs GL5537 Photoresistors. We'd like to settle any problem in a friendly manner. Dark Resistance: 3 Mohm. Light Resistance: 30-50 Kohm.