Ron Guth: The Fugio Cent is one of the most popular of all U.S. "colonial" coins because 1) it is a quasi-Federal coinage (in other words, not associated with a particular colony), and 2) it is available in fairly large quantities in Mint State thanks to the Bank of New York Hoard, which contained thousand of Uncirculated examples.
The cinquefoils refer to the ornaments on the front of the coin: before and after FUGIO and before and after the date. The Four Cinquefoil obverses were combined with a number of different reverse types. This variety has the word STATES on the left side of the label on the reverse (others have raised rims, UNITED on the left side, etc.).
Quality-control was good, but not strict on these coins, thus fully struck, well-centered examples are difficult to locate. Planchet laminations and voids are also common flaws on these coins. For these reasons, the typical grade for Mint State examples is MS62 to MS63. Gem are truly rare, and the best examples include three PCGS MS66BNs.