- In NATO’s world, medical facilities are designated Role 1 to Role 4, depending on capability. A Role 1 facility is essentially a Unit Medical Section, while a Role 2 can do everything short of surgery. A Role 3 has surgical capacity. In Afghanistan, a Role 2 (plus) type of hospital existed in some locations, which was a Role 2 with limited surgical capacity. The all-singing all-dancing full service Role 4 is located at Landstuhl, Germany. At Kandahar Air Field, the United States had been lead nation at the Role 3 until 2005, with Canada taking over the following year. Historical account by Sean Maloney - military historian
So it's basically a MASH unit (mobile army surgical hospital) except it stays in one place.