1.5, works for me on my istick with my little EMOW, anything lower and it's too hard a hit... the Mega's (not EMOW but just plain MEGA, Ed uses 1.0 it just seems to make a nicer "finer" if you will vape. (for us) some like the higher resistance...it's a to each their own kinda deal, try it with whatever batter/mod you're using and see what works for you.