New in the box. Many years ago I sold the Palmer Triline and just discovered this E-Frog was left behind. When used in conjunction with a Palmer Triline this little box allows you to switch between 2 tube heads while only using one speaker cabinet. It places a dummy load is placed on the unused head to prevent damage to the transformers. It’s function is much like the Radial Headbone (which I have in stock) but the Palmer set up (with the Triline) is completely silent and instantaneous which the Headbone can have a slight lag as well as an audible pop. Uses any external on/off jack to switch between heads. Originally sold for $158 but if you need one this one’s new in the box and just $65.