that thing is a piece of poop. don't waste your time ,if you want a primer go for the team associated one and a good filter as suggested.
I tried that thing ,it lasted about 1 min until I figured up it was causing a air leak.
@Nicholas Lowing as other have said, I would steer away from the filter/primer all-in-one as from past experience they tend to leak and be a cause of air leaks as well. Probably one of the best filters you can get for your nitro RC would be a Big Daddy fuel filter from Dynamite.