The Maybach Mb.IV, originally designated Maybach HS, (only related to the Mb IVa by layout and size), was a six cylinder in-line piston engine of 250 hp (190 kW) output, originally developed for use in airships. It was also used for large aircraft such as the Zeppelin-Lindau Rs.I giant seaplane. Variants of the original HS engine included the Maybach HS D and Maybach HS Lu