The Sekonic RT-GX transmitter module seamlessly integrates with the L-858D-U SPEEDMASTER exposure meter and provides comprehensive wireless control for Godox flash systems. This 2.4 GHz transmitter enables remote triggering of compatible Godox flash units from distances of up to 30 meters, featuring 32 channels and 16 groups for precise light control. It supports high-speed sync flash with automatic calculations based on custom ISO and shutter speed settings, eliminating guesswork in complex lighting situations. The module measures flash duration for motion shots and calculates the flash contribution in mixed lighting situations to ensure an accurate balance between ambient light and flash. Additional features include wireless modeling light control and compatibility with the entire Godox ecosystem. Made from durable materials, this compact transmitter offers reliable performance in professional studio and location photography environments. The integration represents a collaborative development between Sekonic and Godox, providing photographers with a unified workflow solution for light measurement and flash control without the need for separate triggering devices.