Lei Shi (Chinese: 雷石; pinyin: Léi shí; lit. 'Thunder Stone'), abbreviated as LS, is a series of precision-guided munitions (PGM) developed by Luoyang Optoelectro Technology Development Center (LOTDC), a subsidiary of Aviation Industry Corporation of China (AVIC). Leishi is a type of guidance kit that can modify existing unguided bomb into guided standoff munition.