Twisted cables are generally stronger than the standard variety and can correct a complaint often mentioned by iPhone owners: that the Lightning cables shipped today are not durable enough for how much they are used.
Thus, many users are required to spend more than $20 on a new Lightning to USB-A or Lightning to USB-C cable.
Apple charges the same price for each cable, regardless of length, on its website.
Apple has never offered a braided version of its charging cable for the iPhone, either for free or for purchase separately. But it does include twisted cables with other products, like the iPad Pro and the HomePod.