 This study examined the Earth's magnetotail over a period of seven years, using data from the cluster mission. It found that dipolarization fronts occur prior to a decrease in BZ, followed by an increase in BZ. These fronts tend to become thinner as the plasma flow increases in speed. The fronts can be divided into two categories, earthward and tailward moving dipolarizations. The fronts are believed to be tangential discontinuities, with the current having a primarily perpendicular orientation. This article was authored by D. Schmid, D. Schmid, M. Vollwerk, and others.