"Sky Loop" is an unofficial name used to describe this rather unique set of inversions used only on Maurer Söhne X-Car-Coaster models to date.
From the side the "Sky Loop" looks like a giant not-so-round vertical loop. The lift hill, known as a "Humpty Bump Lift", is integrated into this element. The lift pulls the train from a horizontal position up a tower vertically. The train is then pulled "beyond vertical", until it is upside-down and nearly above the starting point. This makes the lift ½ of the first inversion. The train then proceeds through a twist called a "360° Corkscrew" by Maurer Söhne. This twist resembles a Heartline Roll, but the train enters this twist while upside-down -- making it an upside-down Heartline Roll. At the twist's halfway point the train will be right-side-up. This point is considered the division of the two "Sky Loop" inversions. Proceeding through the second half of the twist, the train once again returns to an upside-down position completing 1 ½ inversions. The last ½ inversion is essentially the second half of a traditional vertical loop. The "Sky Loop" ends either back at the station or parallel to it if the ride consists of more than just a "Sky Loop".