A solidus of the 9 or 10 day joint reign of Justin II and Tiberius II Constantine, September 26th 578 through October 5th 578.  This is particular piece is the finest of a reported "6 or 7 specimens".  The problem that I have, is that I can only document three additional specimens throughout my library, one is in a contemporary mount, the other has signficant wear on both the obverse and reverse and third is actually a light weight solidus with OB*+*  in exergue on the reverse (shares the same obverse die) .  This piece is the from the Hunt collection, Sotheby's Sale 6055, December 1990, lot 124.  The piece weighs 4.39g and exhibits die clashing of the obverse die at the top of the reverse die.  There is some wear on both the face of Tiberius II on the obverse and the Angel of Victory on the reverse.  Also, as an indentifying mark, there is a flan flake missing to the right of CONOB on the reverse.  Please email me with any information about the existance of any other pieces that I might not be aware of.