KitchenAid K 45
I believe this mixer is older. The rim of the bowl does not appear to be rolled, but flares out flat. The beater, if original, being coated, is another clue. My estimate is early 1970s. Is the color of the white that has "yellowed" a bit? Is the electric plug 2 or 3 pronged? In the mid to late 1970s, KitchenAid changed the governor design and created the "SS" series which is still being made today, called KitchenAid "Classic". If the speed control ever breaks, the parts are no longer available. The parts are not expensive. It can be converted into an "SS" mixer and last for many years if not abused.