Don't loose your Steam Controller dongle!
Uses clip from HpInvent's design, but with this one you don't have to worry about losing the clip itself.
You need to insert the dongle USB first at an angle. It's a little tight so I inserted it from other side straight and then angled it so that it's bended a little. Then inserting it from the inside is easier, still a little force needed to click the dongle into place. It probably won't come out easily without destroying the casing.
The author remixed this model.