Thunder crash bomb
Appearance
![](http://upload.wikimedia.org/wikipedia/commons/thumb/1/19/M%C5%8Dko_Sh%C5%ABrai_Ekotoba.jpg/300px-M%C5%8Dko_Sh%C5%ABrai_Ekotoba.jpg)
The thunder crash bomb (Chinese: 震天雷; pinyin: zhèntiānléi) is an early type of bomb or hand grenade developed in the 12th-13th century Song and Jin-era China. Its shell was made of cast iron and filled with gunpowder. The length of the fuse could be adjusted according to the intended throwing distance.