IPhone TTY Adapter

The iPhone TTY Adapter is an adapter from Apple that plugs into the headphone jack, and allows the user to connect to iPhones.

Support
TTY devices can range from classic s to texting terminals specifically designed for the disabled. TTY support was built into the iPhone 6, negating the need for the adapter on later models, but Apple continues to sell it for 19. On devices without a headphone jack (such as the iPhone 7 and later), only a Lightning to 3.5 mm Headphone Jack Adapter is needed. iPhones running iOS 11.2 or later also support the (RTT) protocol.

Trivia

 * This adapter has been available since the first iPhone was released in summer 2007.