This is the easy obvious crack just to the right of where the roof starts (it basically defines the edge of the roof). The crux is basically right where it passes the roof, but as can be seen from the rating is very easy.
The crack starts out kind of thin (like .75 camalot) and grows until I'm sure you could find a spot for a 6 if you wanted to.
This route ascends the obvious crack to the right of the roof and ends at the anchors under the arch. Make two single rope raps down using shotgun's anchors.