Check the listing for details. Zero Gravity Double Bubble Dark Smoke Windscreen (16-112-19). Condition: New, Made in US. Listed at 118.48 USD. 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 our 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.