The F-Cell is a hydrogen fuel cell electric vehicle developed by Daimler AG. Two different versions are known - the previous version was based on the Mercedes-Benz A-Class, and the new model is based on the Mercedes-Benz B-Class. The first generation F-Cell was introduced in 2002, and had a range of 100 mi (161 km), with a top speed of 82 mph (132 km/h). The current B-Class F-CELL has a more powerful electric engine rated at 100 kW (134 hp), and a range of about 250 mi (402 km). This improvement in range is due in part to the B-Class's greater space for holding tanks of compressed hydrogen, higher storage pressure, as well as fuel cell technology advances. Both cars have made use of a "sandwich" design concept, aimed at maximizing room for both passengers and the propulsion components. The fuel cell is a proton exchange membrane fuel cell (PEMFC), designed by the Automotive Fuel Cell Cooperation (AFCC) Corporation.