SMAKN&reg; SRD-12VDC-SL-C 1 Channel DC 12V High/Low Level Power Relay Module Board Product Name : Opto-isolator 1-Channel Power Relay Module;Coil Voltage : DC 12V Working Type : High/Low Level Trigger;Total Size : 50 x 25 x 18mm/ 2" x 1" x 0.7"(L*W*H) Material : Plastic, Electronic Part Net Weight : 17g Package : 1 x Opto-isolator 1-Channel Power Relay Module