

Download link:
https:

https://www.fontsquirrel.com/fonts/open-sans
https://www.fontsquirrel.com/fonts/exo
https://www.fontsquirrel.com/fonts/pt-sans
https://www.fontsquirrel.com/fonts/Aller
https://www.fontsquirrel.com/fonts/list/tag/helvetica