Thank you for looking. This is the Vertex Overdrive/Booster, Steel String Slight Return Edition. I purchased it at the beginning of March 2026, but I am selling it because I acquired the higher-end SSS model sooner than expected. This is an overdrive/booster designed based on the Steel String Singer amplifier. Unlike the original Steel String MkII, this unit has higher treble, higher headroom, and higher gain. While the original felt like a clean booster, this unit is positioned more as an overdrive. Here are some review videos on YouTube: https://youtu.be/HRPtsgcmHTU?si=vO-uPuFXhjvyR2Hg https://youtu.be/ck29KB8YCbI?si=RuPMeAG1yv5A3gBL overdrive booster dumble sss vertex steel string steel string slight return edition steel string mkii ultra phonix dumbloid unobtanium gladio overdriveland