Original World War 2 business industry trade magazine vintage ad for HYCAR CHEMICAL COMPANY of Akron, OH.  Gasoline Resistance, Another Great Advantage of Certain Synthetic Rubbers. It's synthetic rubber that makes the bullet sealing fuel tank a practical, hard working reality, already credited with bringing back many planes and many more men who otherwise almost certainly would have been lost.  Old 1943 WW2 era propaganda magazine advertisement.