Customers bought our YT-95H-CO2,YT-95H-O2 and YT-95H-LEL gas detectors to install in their tunnels. Then the works want to check these gas concentration before enter in. We sugegst customers to buy our YT-1000H-32 multi channel control pannel to install in their workshop. Hence, workes can view the gas detectors data on the controller before enter in to make sure the safety