What has been identified by Sean O'Connor as Iran's first IRBM field is located 10 kilometers southwest of Tabriz. As of 2008 site consisted of the silo field, an administrative and support area, missile storage bunkers, and an unoccupied HQ-2 surface-to-air missile site. The latter was used as a staging area for mobile Shahab missile transport-erector launchers. The two silos seemed to include blast vents, indicating a hot-launch design.