NewerTech HDMI Headless Video Accelerator, when plugged into display-free (headless) Mac mini's HDMI port, makes host device think display is attached. Consequently, video drivers are loaded and GPU is fully activated. This enables 100% full video performance without any choppy images or mouse lags when Mac mini is used as storage device or media server. Measuring .25 x .68 x .58 in. when plugged in, adapter requires OS X 10.6.8 or later and supports 1080p max resolution.