Double Bubble Windscreen. The Zero Gravity® Double Bubble® has changed the face of the sportbike industry. This innovative "bubble within a bubble" concept was pioneered by Zero Gravity® and has pushed modern day race bikes to their peak performance level. From Zero Gravity®'s first inception of a performance windscreen, the Double Bubble® is Zero Gravity's version of the now popular "stepped profile" design, pioneered by Zero Gravity Racing in the mid-90's. Sculpted to the sport bike's distinctive futuristic lines, the Zero Gravity® Double Bubble® enhances the bike's race look while providing added aerodynamics. Best optics of any windscreen on the market. All are fabricated using highly specialized blow-molding techniques similar to those used to form aircraft canopies; the result is virtually distortion-free optics. Made from the finest grade of acrylic plastic.