A small, insignificant item with a big role. These bungs fit in those holes to help prevent road dust and other contaminants affecting your brakes. On your brake back-plates there are several inspection holes - for checking wear on the shoes and to allow access to the adjusters.
Brake back-plate bung. Fits front and rear brakes on Beetles from 1950 to 1998 and T2 Split Screens from 1950 to 1967; plus front brakes on T2 Bays from 1967 to 1969, plus T25 rear brakes.