The Chain of a Thousand Miles (
The Chain of a Thousand Miles has the appearance of a perfectly normal kusari (鎖分 kusari?, "metal chain"). However, it has the ability to keep extending endlessly as long as its user doesn't allow one of the ends of the chain to be seen. There is a clip on the front end that can be used to connect to other cursed tools in order to extender their range. The chain can also be swung by the user as a blunt force weapon on its own, or both applications at the same time.
Toji Fushiguro kept this cursed tool inside his inventory cursed spirit just like he did the rest of his vast arsenal of weapons. The cursed spirit could hide the back-end of the chain in its mouth, allowing Toji to continue pulling on it to extend the chain's range at will.
In his second fight with Satoru Gojo, Toji connected the chain to another one of his special grade cursed tools; the Inverted Spear of Heaven. This vastly extended the Inverted Spear of Heaven's ability to nullify cursed techniques. With extended range, Toji believed he could nullify the energy output of both Red and Blue of the Limitless.
The sorcerer killer used the chain to break up the ground and send waves of debris at his levitating opponent. Toji possessed great control of the chain, able to guide the Inverted Spear of Heaven through mid-air directly at Satoru. However, Toji was unaware of Satoru's Hollow Technique: Purple, which snapped the chain when Toji was hit with it.