This is an oval shaped Tecumseh foam air filter. It is common on 2 to 9 HP old minibikes and go-karts. It does not fit an original Rokon style air filter. This is the correct length for the longer Tecumseh filter housing but it can be easily cut in half to fit the shorter filter housing.
Tecumseh part number: 29961
Rotary part number: 19-1382