The bbi autosport Porsche 996 & 997 streetcup roll bar features a 2-piece design and 4130 chrome moly steel tubing (1.5" x .120" main hoop & 1.5" x 0.95" rear hoops) for excellent strength to weight ratio. Taking a sensible design approach, the 2-piece construction allows the bar to be mounted to the front seat belt mounts and to the rear strut towers (stronger mounting points), and still be compatible with the factory bose subwoofers. Other similar roll bars on the market are not compatible with the subwoofer. For superior strength and rigidity, the bar utilizes "x" braces on both front and rear sections and each joint has been meticulously tig welded by hand. Bolt-in installation is accomplished by usin...(choose a part on the right to read more)