The Shield type nickel was made possible by the Act of May 16, 1866. Its weight was set at 77-16/100 grains (5 grams), with the same composition as the nickel three-cent piece that was authorized in 1865, and an obverse design similar to that of the two-cent coin. In 1866 the coin was designed with rays between the stars on the reverse. Some of the pieces minted in 1867 have the same details, but later the rays were eliminated, creating two varieties for that year. There was no further change in the type until it was replaced by the Liberty Head design in 1883. Only Proof pieces were struck in 1877 and 1878.