What this coin looks like (obverse, reverse, mint mark location, special features, etc.): This variety of the 1809 Classic Head Half Cent (Penny) features a small circle inside the zero in the 1809 date. This was the result of a larger date being struck over a smaller date which resulted in part of the smaller "0" showing up within the larger "0". This is depicted above in the example image of the error.
Coin value chart: Typical coin prices, values and worth in USD based on grade/condition