Size of Airflow Performance Purge valve line?

I'm in the last stages of assembling my electric fuel pump setup in my fuse, and I need a place to tie in the purge valve return line from the Airflow Performance injection. Can anyone with this system tell me what size line is coming off the divider for this? 1/4" tube seems like it would be plenty, 3/8" would be overkill.

It's a -4 (1/4")

It is 1/4" (AN4).

Vic

Thanks guys - I figured #4 would do it, just wanted to be sure.