Petcock, fuel valve, with 3 positions: on, off, and reserve. Specifically for Ambassador, 1969 to 1972 V7 Special, Eldorado and 850GT fuel tanks, these can also be used on V700 fuel tanks but if you are using the original steel generator covers the right side lever must be shortened slightly to clear. Claimed resistant to 10% ethanol.
Note: Some people have reported that the internal gasket has turned with the handle when these petcocks are new - in order to prevent that, we suggest spraying a lubricant into the valve and working the valve back and forth prior to installation. Also, due to the myriad fuel additives on the market, and different additives being used in different parts of the country, we are no longer able to offer warranty replacements on these valves. These valves have been in use for over 10 years without leaks here in Wisconsin.