This is a recycled u-bend to fit any Dyson DC04.
These were originally made in a myriad of colours and shades, with many different combinations of release catch colour as well. However, any colour variant u-bend is interchangeable across all the DC04 models.
Most are grey in colour. The more popular release catch colour options are available on the choice dropdown above. The "Red" option is the red/yellow one to suit the De Stijl models (on the right of the photograph).
Choose the one that best suits the trim colour on your model.