Thank you to Dave D. for submitting his 3D printed enclosure for RTL-SDR Blog V3 and V4 units. The enclosure is designed to protect and support the dongle. It includes an optional hole for a heatsink to keep the unit cool. Dave writes:

I've designed a 3D printed case for the RTL-SDR Blog V3 & V4. The reason for the case is to use a USB extension to move the weight of the device from the PC USB port to make portable laptop use less likely to fall out or break.

Additionally, there is an opening in the case top to accommodate an optional heat-sink, which may be beneficial with the V3 at higher frequencies.

Here's the link to the 3D print files free on Prusa's Printables website. Anyone can download and print this. Creative Commons applies