Proof Sets issued between the years 1968-1972 are five-coin proof sets. Each set includes the Half Dollar, Quarter, Dime, Nickel, And Penny for that year.  The proof coins for these years were housed in a solid plastic case within a rigid blue cardboard holder. This set contains the 1970 Small Date Cent. 

The "small date" set looks very similar to the large date set. It can take some practice (and magnification) to see the difference. The best way is to look at how the bottom of the 7 lines up with the 0. If the bottoms are even its a small date. If the seven ends below the bottom of the 0 its a large date!