The newly launched Anker 535 USB-C Hub for iMac is currently on offer at Amazon; Prime customers in the US can purchase the device for US$53.99. The gadget has multiple ports, including USB-A and USB-C, with up to 10 Mbps file transfer speeds. Also included on the device are SD and microSD card slots.https://www.notebookcheck.net/Anker-535-USB-C-Hub-for-iMac-has-a-10-Gbps-transfer-speed.629507.0.html
...Does anyone want THAT dangling from their $3,000 Mac?