Tessaiga's sheath

is a scabbard powerful enough to contain the powers of the Tessaiga itself. As such, it is capable of projecting barriers, which Inuyasha uses on multiple occasions to save his life.

History
It was made by Tōtōsai from the donated boughs of the tree yōkai Bokusenō.

During the story
Inuyasha first used his sheath during a battle against the Thunder Brothers. It protected him against many of Hiten's attacks while Tessaiga was out of his reach.

After the battle against the Thunder Brothers, Myōga directed Inuyasha to leave the sword and sheath by a nest of steel wasps, explaining that the wax produced by the yōkai insects would repair the damage the sheath had sustained.

Inuyasha used the sheath to protect himself from Sesshōmaru when he stole Tessaiga from him.

Inuyasha used the Sheath to protect himself from one of Ryūkotsusei's lightning attacks while he was attempting to get the Tessaiga back.

When Inuyasha was trapped inside Tōkajin's gourd, he used the sheath to guide Tessaiga towards the gourd so it would create an opening large enough for him to escape (he was devoured by Tōkajin in the manga and used the sheath to draw in Tessaiga to hit his stomach and cause him to regurgitate Inuyasha).

Powers & Abilities

 * Barrier: it is capable of projecting barriers, which Inuyasha uses on multiple occasions to save his life.
 * Summoning Tessaiga: The sheath is also capable of summoning the Tessaiga from a distance.

Trivia

 * It is not shown how Inuyasha comes into possession of the sheath after obtaining Tessaiga.