64 cuda 273 temperature sender resistance?

So here's I what I find when I search the Napa Online store: http://www.napaonline.com/Search/Detail.aspx?A=ECHTS6178_0275716818&An=599001+101966+50056+2056048+4056061+5999999

But it says "Temp Sender Switch Temp Rating : 15-19 Omh Resistance At 220 Deg F" which has me confused. Any insight?