Sealing Headphones

Sealing Headphones are a pair of headphones that Shiro owns and was given to him by his parents as a graduation from the academy presents. They were given to him to help him deal with his extra sensitive Echo Kekkei Genkai. Due to how powerful and sensitive his Kekkei Genkai is and how it hasn't yet fully developed it often will give him severe migraines. It does so by dampening the noise and using the seals on the headphones to restrain the Kekkei Genkai so it functions on the level of a normal Echo Kekkei Genkai that is being used by someone his age.

As of late the true power of his Echo has been put into question because when put on an adult of the Yamabiko Clan i completely restrains their Echo Kekkei Genkai and they can't hear anything while all it does to Shiro's Echo is restrain it enough for it to be tolerable.

Essentially, the Sealing Headphones are the Echo version of a Taijutsu specialists weight. However, instead of being designed for training purposes, although the usage of these headphones is probably helping his Echo grow even further, they were designed to help hold them back.