World’s Lightest 12.1” Convertible Tablet PC The 3.28 lb. Panasonic Toughbook C1. It features an array of industry-leading advancements, such as being the first rugged convertible to a hot-swappable twin battery design for continuous use. The C1 comes equipped with an 2nd gen Intel Core™ i5 vPro™ processor. The Toughbook C1 is available with a multi touch + digitizer screen for finger and gesture computing and an electronic stylus. The ergonomic strap and dome cradle the hand for comfortable long-term use. The Toughbook C1 features a unique, durable triple hinge design — two hinges for opening and closing the screen, and another hinge for rotating the screen into tablet mode.