The Sekonic L-858D is kitted wiht RT-GX Transmitter module. The RT-GX is a user-replaceable radio module that fits neatly next to the batteries in the SPEEDMASTER L-858D Light Meter.
This kit brings a fully integrated light metering workflow to Godox users, making it possible for them to measure effortlessly, control, and analyze the characteristics of flash like never before. The Sekonic RT-GX simplifies the process of lighting a portrait, analyzing a scene and helping you quickly dial in your lighting recipe to get to your final image with exacting precision.
Sekonic Speedmaster L-858D-U is the world's first multi-function, multi-brand wireless triggering light meter. It is the first of its kind capable of measuring flash duration and brief flash bursts like you find from HSS (High Speed Sync) for precision flash control.
Features
Full Radio CompatibilityThe L-858D with the RT-GX transmitter module enables you to call upon all 32 channels (1-32), 16 groups (A-F,0-9) and Wireless ID's to remotely trigger their Godox compatible lights up to 100ft (30 meters) away. You can even wirelessly control the power of modeling lights as well.

HSS Flash MeteringGodox users can now measure the power of HSS. No need to guess what your exposure is when using High-Speed Sync. Tell the meter your ISO and shutter speed, and it will do the rest.
Next Level Flash AnalysisNow Godox users can more easily measure the