The Hollyland Mars 400S Pro is a wireless video transmission system designed for professional videographers and filmmakers. It allows for real-time transmission of 1080p video and audio from your camera to a monitor or recording device up to 400 feet away, with a latency of only 0.08 seconds. The system is easy to set up and comes with both HDMI and SDI inputs and outputs, making it compatible with a wide range of cameras and monitors. The transmitter and receiver are compact and lightweight, making them easy to transport and use on location. With its reliable and high-quality transmission, the Hollyland Mars 400S Pro is an ideal tool for remote monitoring and video production.