“It demonstrates a significant leap in Iran’s missile capabilities.”-Uzi Rubin, former director of Israel’s Ballistic Missile Defense Organization
Iran developed its Shahab-3 liquid fueled ballistic missile into newer, more accurate, solid fueled replacements called Sejil-1 and Sejil-2.
Sejil is the Farsi word for brimstone. It has been spelled in several ways in English.
Fars News Sejil explainer: