The SF600 has all the features you will need in an adjustable bed. It has all the features of the SF500 plus head-tilt and lumbar support. You can tilt the angle of the pillow section for a more comfortable and natural position for watching TV, using a tablet, or just reading a book before you go to sleep. The lumbar support help to provide more comfort to your lower back. Your Smart Flex base has been rigorously tested, and our commercial-grade steel can hold up to 1,000 lbs evenly distributed.