Model originally uploaded to Thingiverse at https://www.thingiverse.com/thing:2467135.
This is a mini nozzle for the Dyson V6 which is designed to fit cheap 20mm corrugated cable conduit, giving you a flexible hose to clean those hard to reach nooks and crannies in your car.
Basically, you cut a length of 20mm cable conduit, twist it into the end of this adapter, plug it into your V6 and you are good to go! ...because of the narrow bore, it's also pretty loud.
If it's a tight fit, don't force it into the Dyson and risk getting it stuck, just give it a gentle sand and file off the rough edges first!
The drawing included is my rough measurements from the authentic part, and the 3D model differs very slightly from these due to some rounding etc. When I measured the 20mm cable conduit, I found the OD was actually 21mm (presumably this is standard) so the bore of this model is 21mm and includes three teeth to grip the conduit.
The (optional) end piece is a very narrow crevice tool which push fits into the end of the 20mm conduit. This is designed to suit the 16.5mm internal diameter of the conduit. The cross section dimensions of the tool are 12 x 30mm and length is 100mm.
Finally, I can obviously accept no responsibility if it destroys your Dyson, damages your hearing or creates a wormhole in the space time continuum.