The M72 replaced the anti-tank rifle grenade and M20 3.5-inch rocket launcher in U.S. service. According to 3rd Brigade Combat Team, 10th Mountain Division Lessons Learned from March 2010 ...

The RPG-18 is very similar to the US M72-series LAW anti-tank rocket launcher ... no loading/reloading of ammunition is required. The firing mechanism is mechanical and unlike the US M72 series.