Tesla has announced that it is adding a new underbody shield and aluminum deflector plate to the Model S following two collisions that led to car fires last year. The two fires prompted the National Highway Traffic Safety Administration to conduct a four-month investigation, which is now being closed due to Tesla’s design change.

tesla, tesla model s, tesla fire, tesla battery, nhtsa, car safety, electric car, green car, elon musk, green transportation

Tesla says that the new titanium underbody shield will prevent battery fires like the two that occurred last year when Model S drivers collided with road debris. The underbody shield has three layers that are designed to protect the battery. The first is a rounded, hollow aluminum bar that is designed to deflect objects; the second is a military strength titanium plate; and the third layer is an aluminum extrusion that absorbs impact energy.

Related: US Gov Opens Inquiry into Tesla Fires as Elon Musk Defends EV Safety Record

According to Tesla, the underbody shields do not have a substantial impact on the vehicle’s range and will not affect the Model S’s ride or handling. Tesla has started adding the shields to vehicle bodies manufactured as of March 6th, and the automaker will also retrofit the shields on existing cars free of charge.

+ Tesla Motors