This device has two HDMI inputs and four HDMI outputs, so you can switch between two input source devices and send the signal simultaneously to four displays. The unit also has a built in, automatically adjusting amplifier. This means that you can use longer than normal HDMI cables running to the inputs. The unit supports video at resolutions up to 4K@30Hz and high definition audio signals, such as DTS Digital, Dolby, DTS-HD Master Audio, and Dolby TrueHD, as well as standard LPCM stereo. Service & Support : You're never on your own with Monoprice products! We have a full team of friendly and knowledgeable technicians available to answer your questions, both before and after your purchase. Quality at a Fair Price: Monoprice's rugged design and rigid quality control standards deliver high quality products at fair prices.