More info and a demo video by blackfox herself, in the members area!

A grenade is essentially a small bomb, but works like a simple firecracker. A firecracker is made up of a paper body filled with gun powder containing a small fuse. When the fuse is lit, it burns down to the powder and causes the gun powder to explode. A grenade works exactly the same way, except that a mechanical device instead of a match lights the grenade's fuse.