00016 is a Natural Gas smart gas valve by Honeywell used on Mr Heater, Enerco, and Heatstar units .
The 00016 Honeywell model SV9510K2166 is a direct spark ignition gas valve that features a ON-OFF lighting sequence and uses 1/2" pipe thread for gas inlet and outlet. 00016 Honeywell smart valve has a built-in diagnostic program, which will assist in troubleshooting in the event of a valve-related problem.
The LED is located on the top of the valve as shown in the pictures above.
This 00016 Natural gas valve is the gas valve on the following Natural Gas Heat Star ERXL units: