Black Receiver

These cylindrical black rods, originating from the Demonic Statue of the Outer Path, allow the user to transmit their chakra across vast distances through an application of the Outer Path's ability. According to Shizune, these rods act as high-frequency chakra demodulators, which become appreciably warm to the touch whilst currently receiving chakra. They possess incredible durability, damaging every scalpel Shizune used to extract just a small sample during her autopsy of the first Animal Path, and even displaying some resistance when struck by Naruto Uzumaki's Rasengan.

To create his Six Paths of Pain, Nagato implanted the receivers into a number of corpses at various points along their body, much like piercings. Doing so allowed him to transmit his chakra into the bodies and control them remotely as if they were his own, while bestowing each with certain abilities that Nagato wielded thanks to his Rinnegan. The many animals summoned through the Animal Path technique also had a number of these body piercings, suggesting that Nagato controlled them in a similar manner. When using the Summoning: Demonic Statue of the Outer Path, several of these receivers were pierced into Nagato's back in order to allow him to transfer his chakra to the statue and in doing so, manipulate it.

During the course of the Fourth Shinobi World War, Tobi utilised these same rods to control his own Six Paths of Pain comprised entirely from reincarnated jinchūriki, using only one receiver per body. By using them to manifest chakra chains, he was able to maintain authority over even the tailed beasts sealed within the jinchūriki, while retaining a connection between the beasts and the Demonic Statue. He later demonstrated an apparent weaponised variant of the receivers that took the form of gigantic stakes, kept stored within a separate dimension, which automatically generated these chakra chains in response to a tailed beast's power when inserted, in an effort to both bind and suppress it.

Madara Uchiha has used these to store his will.

Trivia

 * Nagato has also used modified versions of these receivers to act as blades, allowing him to disrupt his opponents' chakra flow by transmitting his own chakra into their bodies when pierced.
 * The main difference between this and the Chakra Disruption Blades is that these begin transmitting chakra to his Six Paths of Pain when they are activated. Nagato also seemingly went to some lengths to retrieve them. The disruption blades on the other hand, are used in battle and only transmits chakra when Nagato wants.
 * It has been shown that the receivers inserted in the revived jinchūriki move position when they go through a transformation and get bigger. As seen with Rōshi as he transformed into Son Gokū's full form. It moved from the chest, up to its neck.