what size wrench do I need to remove the injector ?

My comb wrench set stops at 19mm and I'd like to buy the right size, the first time.

ALSO: THE TUBES that connect the inmjectors to each other. Do it juts yank them off ?

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1985 300D : the clean one 180k miles - Now passed onto my parents.
2000 E39 M5
2002 e46 330xit
1991 mustang notch (project)
1970 chevelle (project)