Ross Flanger (1978)
The classic version, made in Kansas. MXR later stole this design part-for-part and sold it as their M-117 Flanger. I don't know if Ross ever sued, though. Both companies were out of business by 1984. The MXR brand and product lines were resurrected by Dunlop in the early 1990s. ‎- Smooth Young Priest