Huo Guan (火罐)

Drawing of a Huo Guan, from 'Wu Bei Yao Lue (《武備要略》)'.

Huo Guan (火罐, lit. 'Fire jar') is a ceramic grenade used in naval warfare. It is a large ceramic pot filled with explosive gunpowder, poison smoke powder, firecrackers, Di Shu (地鼠), fragmentation and caltrops. When thrown, Huo Guan will break and explode upon impact, spreading fragmentation and caltrops over a large area. The erratically moving Di Shu distract the enemy, causing them to be more likely to step on the caltrops amid the confusion.

Guo Xing Ping (國姓瓶) can be considered a subtype of Huo Guan.