Does anyone know what the below device is used for and how it works?
http://www.generac.com/uploadedFiles/Assets/SpecSheets/0186670SBY-E RTS 100-400 Amp Generac DLM.pdf
http://www.generac.com/uploadedFiles/Assets/SpecSheets/0186670SBY-E RTS 100-400 Amp Generac DLM.pdf