From their website:
With inspiration from fans, UTG is happy to release three new attribute elements for building custom combatants. In addition, three new combatants are included with this Bonus Combatant Pack. Anti-Aerial is a new Ranged Weapon Feature that allows a combatant to specialize in attacking flying targets. Portable is a new Ability that allows a combatant to be easily transported. Impeded is a new Liability that reflects a combatant’s limited flexibility while moving.
These new rules are fully combatable with the over 270 Abilities, Liabilities, Weapon Features and Flaws found within the Vortex: Core Rulebook. The Vortex Bonus Combatant Pack is available for free from www.UnifiedTheoryGames.com.
Vortex is a customizable miniature skirmish game that can be used with any miniature in any setting.