Black Receiver

These cylindrical black rods 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's Rasengan.

Nagato upon summoning the Demonic Statue of the Outer Path during his confrontation with Hanzō of the Salamander was pierced by several of these all of which originated from the navel of the statue. From there, he incorporated their use in his Six Paths of Pain technique, where he 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.

It was later revealed that Madara, before dying, materialised his will into these receivers and left it protruding from the navel of Hashirama's living clone and instructed Obito to use it for his revival. Because these receivers originated from Madara, he has the ability to manipulate anyone who carries these in their bodies.

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. Obito employed them as stakes to bind the power of tailed beasts.
 * 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 transmit 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, he transformed into Son Gokū's full form. It moved from the chest, up to its neck.