The iPad Pro's USB-C port is great. It should be on my iPhone, too - CNET
uni® USB C to 3.55mm Hub for iPad Pro w/ USB C Headphone Jack, 4K HDMI
Lightning to USB iPhone ipad 変換アダプタ Lightning to USB 機器接続 OTG USBメモリ接続 データ転送 OfficePDFファイル :zj05-A:大良商店 - 通販 - Yahoo!ショッピング
Amazon.com: iPad Pro USB C Hub, NewBEP 7-in-1 Hub Adapter for iPad Pro, iPad Air 4, USB C Computer, with 4K HDMI, 60W USB-C PD Fast Charging, 3.5mm Headphone Jack & Type