The kunai (クナイ, Kunai), along with the shuriken, is one of the most common ninja tools. It is a black dagger with a handle wrapped in bandages and a small ring attached to the end of it. The kunai is designed for thrusting and stabbing, though it can still do some damage if thrown despite not being designed for it, and is about the length of one's hand.
Many shinobi attack by attaching an explosive tag to the blade. The kunai is usually thrown so that it lodges in an object near the target, and then the explosion from the attached tag destroys the target. This use of the weapon is known as an explosive kunai (起爆クナイ, kibaku kunai).