BM-21 Grad (GRAU Index 9K51) is a multiple launch rocket system of 122 mm caliber. 2B17 - BM-21-1 RSZV 9K51 combat vehicle on the Ural-4320 chassis. The main elements are prepared for TurboSmooth smoothing (2 iterations). The elements of the hull, weapons, and chassis have been worked out. The launcher rotation and the angle of attack have been adjusted.