Included with the SkyView 5.0 software update is an update to the transponder that moves it from TSO C166a to TSO C166b compliance. This means it’s fully compliant with the 2020 ADS-B mandate for 1090ES. Installing the software update requires that the transponder be simultaneously labeled to indicate TSO C166b approval. Apparently, not applying the label renders the transponder unairworthy according to the FAA.