Star Wars: Legion - B1 Battle Droid Upgrade Exp.

Star Wars: Legion - B1 Battle Droid Upgrade Exp. - Rules of Play says:

The B1 Battle Droids Upgrade Expansion contains four unpainted, finely sculpted B1 Battle Droids different from those found in the Clone Wars Core Set or the B1 Battle Droids Unit Expansion. These miniatures arrive on frames, giving you freedom to customize their appearance. On the battlefield, these miniatures can become the basis for a new unit of B1 Battle Droids, or you can use the new heavy weapon and personnel upgrade cards options they bring to enhance your existing units.