Radiodetection RF Marker Ball – Gas (Yellow) The Radiodetection RF Marker Ball – Gas is a passive underground marker designed for identifying buried gas lines. RF marker balls are passive, frequency-tuned markers that resonate when energized by a locator signal, enabling accurate underground utility identification without power or maintenance. Installed at key points such as valves, bends, and crossings, it can be accurately located using Radiodetection marker ball locators including the MRX SG, MRX G, and MRX. Yellow color coding follows standard conventions for gas utilities and enhances on-site safety. Utility Type: Gas Color: Yellow Part Number: 61/OMGAS-MK2 Packaging: Box of 30