S-2A Propane / CNG Monitor and ControlThe S-2A propane monitor / controller features include low current draw plug-in sensors (second sensor optional) display module fault light / alarm and fault light / alarm to indicate a malfunction in either one of the sensors, (Fault indicators show that the module or sensors are not working and may need repair, )MS-2 sensor and 1 SV-1 solenoid valve included, The system is calibrated at 20% LEL (lower explosive limit) to eliminate most nuisance alarms while allowing enough time to take action, A microprocessor-controlled two-channel monitor with automatic solenoid valve on / off switchA ""press to test"" button for each channel confirms functionModule size: 4-3/4"" x 3-3/4"" x 7/8""Product : XINTEX 2 CHANNEL PROPANE/CNG MONITOR & CONTROL W/ONE PLUG Manufacturer : XINTEX / FIREBOY Manufacturer Part No : S-2A UPC : 619749211723 SKU: CW28162