Šarma-Adad II, son of Šu-Ninua, reigned for three years according to the Assyrian King List [/riao/kinglists/assyriankinglist/assyriankinglist/index.html#BelubaniDynasty] (AKL). No royal inscriptions are known from his reign. Reade 2001 suggests that Šarma-Adad II came from the city Ekallātum and that he may in fact be identical to Šarma-Adad I.
Poppy Tushingham
Poppy Tushingham, 'Šarma-Adad II', RIA 1: Inscriptions from the Origins of Assyria to Arik-dīn-ili, The RIA Project, 2023 [http://oracc.org/oldassyrianperiod/belubanidynasty/sharmaadadii/]