What is the fuel mix ratio for the echo pb-2100?

I have a pb 2100 made in 2000 all my echo prouduct's call for 89 octane fuel and echo two stroke oil mixed 50-1 . I run the same mixture in my pb 2100 , pb 251, and pb 250 leaf blower and even my srm 225 weedeater. So this is the correct mix to use in anything that has a two cycle motor.