Paul Chavand, founder of Rollkers SAS, displays the prototype Rollkers transportation device he invented during a press event at the Mandalay Bay Convention Center for the 2015 International CES in Las Vegas, Nevada, Jan 4, 2015. The product is not a skate; it balances for you and when you place it on the bottom of your shoe, it gives you the ability for faster transportation based on walking.[Photo/CFP]