These are a variation of the chakra receiver. Much like the simpler chakra receiver, the user is capable of channelling their chakra through it. During the Fourth Shinobi World War, Obito Uchiha employed these against Naruto Uzumaki and Killer B. Obito keeps them stored in another dimension, and can readily deploy them. Upon retrieval, Obito can eject them with enough force to pierce rock, as well as the flesh of fully transformed tailed beasts. Also like the simpler chakra receiver, Obito can manifest chakra chains through them, with which he is capable of binding the powers of a tailed beast.