The 700-200 Series snap-action and snap-throttle (modulating) hydraulic controls are combination gas valves, thermostatically operated by a remote temperature sensing bulb. Two types of temperature adjustment models are available. One type is a single capillary model with the temperature adjustment knob on the gas valve itself. The second type is the remote dial, dual capillary model designed for cabinet mounting. These have an 18" capillary from the valve to the sensing bulb and a 48" capillary between the bulb and the remote temperature adjustment knob.