You insert an SD card under the USB contacts and connect it. Your computer :-) I use it to store boot files for one of my ESXi hypervisors in the home lab. Works great and you can't get a smaller footprint.
IDENTIV USB Smartfold Type C SCR3500C
11 Review
TP-LINK UH700 USB Hub, 7.1cm Ports, Black
12 Review
Neewer Black Memory Card Storage Holder - Waterproof, Anti-Shock with 14 Slots for Micro SD, TF, CF, SD and XD Cards
12 Review
π» LEEGLOAD 4 in 1 SD Card Reader Adapter for iPhone/iPad/Android/Computer and Digital Camera, Memory Card Adapter with USB C/USB A/Micro USB, Trail cam Card Viewer (Black)
13 Review