Indicator light: one green for switch, red one for power.Built in a potentiometer for sensitivity control.The module with Photoelectric Switch Sensor Relay Module, can be use in street lamp ,automation equipment, detecting the brightness, etc.Product Name: Photoelectric Switch Sensor Relay ModuleMode: Light Actuation ModeWorking Voltage: DC 12VRelay Loading Voltage: AC 250V 10A,DC30 V 10APCB Board Size: 50 x 25mm/ 2" x 0.98" (L*W)Sensor Size: 60 x 20.5mm/ 2.4" x 0.8" (L*W)Cable Size: 50cm/ 20"Mounting Hole Size: 3mm/ 0.12"Material: Electronic Components, PlasticPackage Contents:1 x Photoelectric Switch Sensor Relay ModuleOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.