Lenovo Flex 4 1580 Convertible 2-in-1 Laptop: Designed for those who want to be different, the Flex 4 has a number of features that set it apart. The palm rest is framed with a unique diamond cut bevel. It's also thinner and lighter than previous generations and has double the storage too, so you can say goodbye to external hard drives. Along with great battery life, the Flex 4 can be used in four different modes to suit your needs.