Unbreakable focus modifier

[McBain]

Heroes 5th ed gives a focus 3 types of durability; fragile (-1/4), durable (+0), and unbreakable (+?). What is the modifier for unbreakable?

[Steve Long]

There is no modifier for Unbreakable. Breakable and Unbreakable are the two basic choices; Fragile and Durable just provide costs for customizing Breakable, if that's what you want.