The cone surround can be rubber or polyester foam, treated paper or a ring of corrugated, resin coated fabric; it is attached to both the outer cone circumference and to the upper frame. These diverse surround materials, their shape and treatment can dramatically affect the acoustic output of a driver; each implementation has advantages and disadvantages. Polyester foam, for example, is lightweight and economical, though usually leaks air to some degree, but is degraded by time, exposure to ozone, UV light, humidity and elevated temperatures, limiting useful life before failure. Treated paper surrounds will eventually fail.