Similar to a slalom the weave poles are a series of upright poles each about 3 feet (1 m) tall and spaced about 20 inches (50 cm) apart. It is one of the most difficult obstacles for a dog to master. It varies from 5 to 12 poles at one time. The dog must always enter with the first pole to his left and must not skip poles while weaving in and out until the end.