The Bubble is similar to the E.V.A. Suit, but it is for machines, buildings, and vehicles (except for the Ace). It is the same price as an E.V.A. Suit, but the Pro is different. It is filled with Aerogel, a new terrain type that is like a combination between land and water.
The Pro version increases range of the towers inside the bubble, and it gives a special ability that makes the bubble have the equivalent of a Level II Shield around the bubble, and it can triple the fire rate for the occupants.