Morgan's first obverse design of this type without pellets between the words in "E Pluribus Unum" combined with his reverse with pellets before and after "Five Dollars".
These were struck on thinner and slightly wider 25.5mm vs 21.5mm planchets than the regular issue.
About a half dozen are known, several of which have been gilted.
This obverse die was also used on J1568A/P1759 and J1569/P1760 and the reverse was also used on J1572-J1573/P1761-P1762.
A copper reverse die trial, JA1878-3/P3458 is also known.
Photos courtesy of Heritage.