i think you'll find that that means a double seal - a kinda first one and then one a bit further in. maxspiced go to gary grover or !! for the steel backed type.
If you are trying to remedy coolant leaking out of the weep hole you might not only need the seal but also the balancer shaft o-ring p.n. 0770 010013 (for an 05 but I believe its the same as yours) and the water pump bearing which also has a seal of sorts glued to it.