A groundbreaking addition to your photography toolkit, the Sekonic L-858D-U Speedmaster Light Meter Kit, equipped with an RT-GX Transmitter module, offers a seamless, integrated light metering solution for Godox users. This advanced light meter kit is designed to simplify and enhance your lighting process, whether you're capturing a detailed portrait or analyzing a complex scene. The RT-GX Transmitter module, a user-replaceable component, fits conveniently next to the batteries in the Speedmaster L-858D Light Meter. This innovative design allows for effortless measurement, control, and analysis of flash characteristics, enabling you to fine-tune your lighting recipe with unparalleled precision. The Sekonic Speedmaster L-858D-U stands out as the world's first multi-function, multi-brand wireless triggering light meter. It's a pioneer in its ability to measure flash duration and brief flash bursts, such as those found in High-Speed Sync (HSS), providing you with precise flash control. The L-858D, when paired with the RT-GX transmitter module, offers full radio compatibility. It empowers you to access all 32 channels (1-32), 16 groups (A-F,0-9), and Wireless ID's to remotely trigger your Godox compatible lights from up to 100ft (30 meters) away. This feature also extends to the wireless control of modeling light power. With the L-858D-U Speedmaster, High-Speed Sync (HSS) flash metering becomes a breeze for Godox users. There's no need to guess your exposure when using HSS. Simply input your ISO and shutter speed, and the meter will handle the rest. This light meter kit takes flash analysis to the next level. It allows Godox users to measure the percentage of flash in their images accurately, ensuring the perfect balance between ambient and flash lighting. Additionally, it measures flash duration, letting you know the stopping power your lights possess, whether you're capturing the sweat on an athlete or the flowing gown of a fashion model. In conclusion, the Sekonic L-858D-U Speedmaster Light Meter Kit with RT-GX Transmitter module is a durable, high-quality, professional, reliable, and advanced tool that is compatible with Flashpoint, Godox, and other popular brands of off-camera flashes and lighting equipment. It's an essential tool for photographers seeking to elevate their lighting and image quality.