This 1963 Franklin half is double-struck, with the first strike in collar, then the coin failed to be ejected from the collar entirely and was struck again, creating a partial collar strike with reeding on both "edges" of the partial collar. There are other minor signs of the double-strike on the obverse and reverse, but primarily it is visible on the edge.
Franklin half double-strikes are extremely rare, and are in fact probably scarcer than Franklin halves on cents or nickels (which sell for $5,000 or so.) This is the first Franklin half double-strike we have ever had in stock, and they almost never come on the market for sale.
PCGS AU detail with a counting wheel mark on the reverse. A decent looking coin, and the wheel mark on the reverse only barely detracts from the coins appeal (probably 1/5 of all errors have counting wheel marks!)