NGC 5c 1977-S Proof Jefferson Nickel on copper cent planchet. The coin is brilliant red, due to being struck on the copper planchet, and also is slightly smaller than a normal nickel. It weighs 3.1 grams, much less than a normal nickel (which weighs 5 grams.)
Strong clashed dies on the reverse, and fairly strong on the obverse as well.
Proof nickels on cent planchet are overall rare. There are just a small number known (maybe 15 or so) for all dates and grades.
PF66 Ultra cameo with blazing red luster, and frosted devices. Some light contact marks or scuffs account for the coin's not grading a higher grade.