The 138190053A paper Air Cleaner Spacer Gasket connects the stock airbox or aftermarket filter adaptor to the carburetor. 

Depending on the air filter adaptor, you may require the thinner paper gasket over the thicker metal gasket. This gasket will usually properly space the air filter out to tighten the carburetor assembly to the head. The gasket only goes on one way to match the air bleeds and carburetor inlet shaft. If installed incorrectly, it will block the inlet and air bleeds, which will cause tuning problems and restrict airflow to the carburetor. 

The Air Cleaner Gasket fits most of the 196cc 6.5hp Clone Carburetor including Honda GX200, Ducar 196, Ducar/Tillotson 212E, Tillotson 196R/RS, Tillotson 212R, Ducar/Tillotson 212E, Predator 212, and BSP 196 and 212 Carburetors