The defense sets up with the first two rows in the shape of arrows. The 2 and 5 defenders are two steps in front of the other defender in their row. The defender guarding the disc plays a "flat" mark, not forcing the throw to one side or another.
As the disc moves to the sideline, the entire defense shifts over. The 4 defenders main job is to quickly cut off the upline throw, while the 1 defender plays a "flat"mark. The five defender slides into the gap between the 1 & 2. The 6 defender slides over slightly and is responsible for any throws over the top, across the field.
As the disc is swung to the opposite side of the field, both defensive lines slide over, with the 3 defender playing a "flat" mark. The 6 defender quickly sprints over to cut off the upline throw, while the 5 defender fills the gap between the 2 & 3 defenders.
The zone works to encourage throws between the handlers, with the defenders keeping the disc in front of them instead of attempting to cut off the handler throws.
Eventually, the handlers will get bored/frustrated and try to throw the disc up the middle, where the 5 defender will be able to cut off the pass.