de Grisogono celebrates 15 years of the black diamond with this model. The case is forged in gold with a black PVD coating and is set with 184 black diamonds. Its automatic movement powers dual time with date functionality. The Instrumento N˙ UNO DF S4’s dial features 147 black diamonds with a guilloché design and gray Arabic numerals. Finishing the timepiece, a black galuchat strap.