The Archer Select is a uniquely functioning Boost/Overdrive. Experience K style overdrive while being able to switch between 7 different clipping diode options including the diodes found on the Archer, iKon and JB model. If you leave the clipping diode foot switch off it defaults to the stock diodes. With the clipping dial you can choose between 6 additional clipping diodes ranging from lowest to highest output. Depending on which diodes you have the selector knob on you can A/B between the stock diodes and the selected diodes. An added D.I. Speaker Simulator is included for those who like to be able to monitor their OD sound via direct or have the option for direct recordings. The ground switch is solely there for the D.I. in case you have grounding issues.