This 3/8" to 1/4" Adapter Screw is super handy if you're building projects that connect to a tripod or a camera. It's a simple fix for getting a tripod with a 1/4" machine screw fastened onto a camera with a 3/8" thread nut.
It's also very handy when 3D printing an enclosure that will connect to a camera/tripod because you can make a 3/8" hole and then glue this in. That way you get nice strong steel threads and aren't relying on your 3D print to match nicely with a 1/4" mount.
Adafruit Product Page: https://www.adafruit.com/products/2392