The 700 millivolt gas valves are wall thermostat actuated combination gas valves. These controls combine a manual gas cock, automatic pilot safety valve and a millivolt operator. The automatic pilot safety is separate from the gas cock and provides gas shutoff in case of pilot outage. Regulated and non-regulated models are available. Standard features include: pilot outlet, pilot gas filter and pilot adjusting key. Valves can be mounted in any position except upside down. Most appliances manufactured in the USA and Canada are manufactured to meet the standards set forth by the American National Standards Institute (ANSI). A revision in the standards "mis-wiring requirements for gas valves" was effective January 1, 1996. The reason for this standard was so that you as a service technician could disconnect the gas valve wires and reconnect them without making a mistake. Therefore all Robertshaw® millivolt gas valves now meet the new standard. The 700-500 series millivolt gas valves have a 1/4" quick connect terminal and a 3/16" quick connect terminal on the terminal block. There is NO terminal screw (or threads) on the side that has the 3/16" terminal. If your old application used a terminal screw, you will need to use the 3/16" adaptor terminal that is included with this gas valve. Does not apply to 700-502, 700-504, 700-506 and 700-511 which have the coaxial connection. Will accept both types of thermopiles (coaxial or 2-lead). Use 1751-003 to convert valves to Natural Gas. Use 1751-013 to convert valves to L.P. Gas. Will only work with two-lead thermopiles (Unless otherwise noted). Pressure regulator conversion from natural to LP (1751-013). LP to Natural (1751-003). Excellent replacements for Gas valves. Diaphragm valve only-no gas cock or safety magnet.