Amazon Link Below... Quick review of the 200W KATs Handi Heat Magnetic Heater. I use this on the oil pan of my 354 International Harvester Tractor in cold weather to improve cold starts.
https://www.amazon.com/gp/product/B000I8TPFU?pf_rd_r=EPQF1RJKKTXEWJR9K3JV&pf_rd_p=5ae2c7f8-e0c6-4f35-9071-dc3240e894a8&pd_rd_r=24e29808-dfaf-4a7d-a892-d9fe4886406d&pd_rd_w=1E11S&pd_rd_wg=ehLo9&ref_=pd_gw_unk