Yamaha Ef2000is Generator Dipstick Oil Filler Fuel Cap WARNING: ONLY GREAT RIVER COMPANY SELLS GENUINE PRODUCT - The only authorized seller of GREAT RIVER COMPANY MAGNETIC DIPSTICK, NO MESS OIL FILLER, EXTENDED RUN FUEL CAP Use this gas cap to extend the range of your generator with a external tank. Built in Super Magnet helps keep metal fragments from harming your generator. Built in funnel making adding oil more convenient. Made in the USA by Great River Company Inc.