What size slot do I cut for Air Vent's ridge vent?

Ridgepole Construction - Cut 3/4" slot on each side For truss construction- Cut a 1.5" slot at the peak of the roof

For ridgepole construction, cut a 3/4" slot on each side of the ridgepole. For truss construction, cut a 1.5" slot at the peak of the roof.