The Key Visual Phone USB Adapter was released in Japan in December of 2017 by A3. It features art from the anime series that released the same year.
This USB Adapter was released as merchandise for the UQ Holder! anime that aired in the fall season of 2017. It has a charging and connection compatible USB 2.0 cable with a output of 2.4A. It has a reel-style USB cord that reaches 90cm.