DOP17660MS660 Stihl MS660 Fuel Tank Vent With Grommet No. 1122-353-9200. This is a quality aftermarket Stihl MS660 fuel tank vent that includes the grommet. It replaces OEM tank vent numbers 1117 350 5800 and 11173505800, and OEM grommet numbers 1122 353 9200 and 11223539200.