The Radial Highline Stereo is a two-channel passive line isolator tailored for connecting guitar and amp modelers to a PA or recording system for live tours and studio use. It uses premium Jensen 1:1 transformers to deliver unity-gain signal integrity while providing galvanic isolation that eliminates ground-loop noise and blocks phantom power, ensuring clean, distortion-free tone. Stereo ¼″ inputs feed both Thru and XLR outputs; two “Sum” switches let you sum either the Thru outputs or the XLR outputs to mono, providing flexibility for local monitoring or reduced mixer channels. Designed with a rugged steel housing and long-life switches, it requires no external power and delivers ultra-wide frequency response, minimal distortion, and high reliability.