Cummins Onan Transfer Switch 150 Amps, 1997, 3 Phase
ONAN 225 AMP OT TRANSFER SWITCHING ASSEMBLY 306-1409 FITS OT 225 AMP | eBay
Onan Automatic Industrial Transfer Switches for sale | eBay
RST200 Onan Automatic Transfer Switch 200A
found this big onan transfer switch in our basment, anyone know how old this is, of its oversized or what these switches do? There are replacment spark plugs for what i assume