Need help with a part I.D & symbol ?

[fredx]

I have no idea what this black gizmo to the left of the toggle switch is, also can anyone tell me what those three symbols embossed in the body mean

 

[SimonHS]

The gizmo is a fuel tank vent, to prevent a vacuum forming in the tank when the fuel level drops.

The symbols are summer and winter settings. There will be a shutter to let normal air into the carb during warm months and air heated by the engine into the carb when the weather is very cold. You can leave it on summer almost all the time, unless you cut a lot of wood in sub zero temperatures. Don't set it to winter in warm weather.

 

[fredx]

Thanks Mr. Simon