I think they left out a 2 it should have been 220 mm. rockets.
The 9P140 Uragan ('hurricane'), known as the BM-27 began its service with the Soviet army in the late 1970s as its first modern spin and fin stabilized heavy multiple rocket launcher. This system is capable of launching 220mm rockets from 16 launch tubes mounted on the rear of a ZIL-135 8 by 8 chassis.