This is a really cool line selector pedal that lets you toggle between two different effect loops, or blend them together, or bypass them altogether. It has 6 modes: A/B, A/BYPASS, B/BYPASS, A/B/BYPASS, A+B/BYPASS, A/B/BYPASS.
As one example, I used it on A+B to blend the dynamics of a dry guitar signal on line A with an overdriven signal on line B, which gave great results.
Fully functional, works great, and in mint (like new) cosmetic condition, with box. Power adapter not included.