https://www.cnet.com/news/ipad-pro-computing-future-comes-closer-with-hyperdrive-usb-c-hub/

It takes as much advantage of the USB-C port as Apple allows, letting you plug in 3.5mm audio devices, HDMI monitors and TVs, regular and micro SD memory cards, your charger and other USB-C devices, and accessories like Ethernet adapters that use the old-style rectangular USB-A connector that's been a fixture on laptops for decades.

The Sanho HyperDrive USB-C Hub attaches to an iPad Pro's USB-C port.