aluminum to function, carrying up to while hovering above the surface. Four engines were used to power the magnetic levitation, with the option of applying thrust and spin to the board under user control. The prototype was promoted in a campaign on Kickstarter the day of the news coverage, with a price of $10,000 for the first ten boards. The New York Times said that although the board worked, Greg Henderson had no personal interest in skateboarding and that the Kickstarter was "basically a publicity stunt," designed to call attention to his company. On 24 June 2015, Lexus released a video as part of their "Amazing in Motion" series purporting to show a real hoverboard they had developed, the Slide. It was stated by Lexus that the board worked using liquid-nitrogen-cooled superconductors and permanent magnets. The board was shown moving over a conventional-looking concrete skateboard park surface, which led to some skepticism. Lexus apparently later admitted that it only works on special metallic surfaces and the surface shown was not just concrete. On August 4, 2015, Lexus revealed the working principles of the Slide hoverboard with a promotional campaign, filmed in Barcelona and starring Ross McGouran, a professional London skateboarder. Lexus released a series of videos explaining the technology and the whole engineering, research, and development process in association with all its partners. Other In March 2014, a company called HUVr claimed to have developed the technology for hoverboards, and released a video advertising the product on YouTube featuring Christopher Lloyd, Tony Hawk, Moby, Terrell Owens, and others riding hoverboards through a parking lot in Los Angeles. Special effect failures such as incomplete wire removal have conclusively identified the video as a hoax or joke, traced to the Funny or Die website through identification of the cast and public references to the project. Funny or Die later posted a video featuring Christopher Lloyd "apologizing" for the hoax. Rumors circulated in 2001 that inventor Dean Kamen's new invention, codenamed Ginger, was a transportation device resembling a hoverboard. In reality, Ginger was the Segway Human Transporter, a self-balancing two-wheel electric scooter. Guinness records Guinness World Records defines a hoverboard as an autonomously powered personal levitator. In May 2015, the Romanian-born Canadian inventor Cătălin Alexandru Duru set a Guinness World Record by travelling a distance of at heights up to over a lake, on an autonomously powered hoverboard of his own design. On