Press Mode and + sign together to change °F from °C or vice-versa
Cross verified infrared vs tushti thermometer...always varying + or - 1 ...not sure which is accurate reading
I got this Oxymeter for myself and its working great.
Good quality product. Fasat delivery. Satisfied.
Just an update, i went through the youtube video and managed to figure out the rather complicated menu options to switch to Fahrenheit.
However would still recommend that you send the machines to people with Factory default of Fahrenheit - that would be truly made for Indians!