The 15 cm schwere Feldhaubitze M 94 was a heavy howitzer used by Austria-Hungary in World War I. It had a bronze barrel and relied on wheel ramps to absorb its recoil. The barrel was modified in 1899 as the M 99 and can be identified by its octagonal shape. Both howitzers could be mounted on a wide variety of carriages to suit their mission, including a carriage only 1.13 metres (44 in) wide for mountain use. Around the start of the 20th century both the M 94 and M 99 were modified to increase their elevation up to 65°. The elevation arc had to be extended and the trunnion mounts and wheels had to be strengthened to withstand the greater recoil forces when firing at high elevation. They were known as the M 94/4 and the M 99/4 after modification.