Only used for review. In perfect condition Retails for $549 Asking $399 Features & details Transmitter, Receiver and Monitor All-in-One - Hollyland Mars M1 is an innovative design of wireless video transmission system that also combines the function of camera field monitor all in one, for a more effective recording and monitoring experience and complete freedom of movement on the set. Switched to transmitter/receiver mode, it can be paired with Mars 4K/400S Pro/300 Pro. As transmitter, it supports APP monitoring up to 4 mobile devices at the same time Stable Transmission with Ultra-Low Latency - Mars M1 achieves LOS range of 150m for greater operational freedom and ultra-low latency of 0.08s for faster and more accurate real-time monitoring. The intelligent channel scan allows you to find the interference-free channel option for a stable connection experience. Supports scan function and manual channel selection Dual SDI & 4K HDMI Interfaces - The Mars M1 field camera monitor and wireless video transmission supports up to 3840x2160p30 HDMI IN & LOOPOUT. In addition, Mars M1 supports HDMI/SDI input and HDMI output of 23.98/29.97/59.94fps formats, providing greater flexibility for broadcast and production technical standards and more compatibility across production and post-production 5.5" LCD Touch Screen with Professional Color Calibration - With a daylight viewable brightness of 1000nits, the standard Rec.709 color gamut and 16.7 million natural colors, the Mars M1 camera monitor can guarantee accurate and reliable viewing results, to ensure your eyes are not deceiving you. The resolution is Full HD 1920x1080 with an aspect ratio of 16:9 and a contrast ratio of 1000:1, with several levels of color temperature settings (default 6500K) Multiple Presets Available - Give the image a completely different and extremely attractive look. Five selectable 3D LUT presets to map the colors to the monitor for a consistent, high-quality effect. The Mars M1 Monitor also has other auxiliary functions, such as Focus peaking, 4x and 2x zoom, zebra, false color, frame guides, cropping, screen freeze, waveform, horizontal/vertical flip, and even more to increase your shooting efficiency