This a recycled bottom filter flap (also known as a bin catch) in yellow, suitable for any HEPA variant of the Dyson DC01. The one supplied will be as per the photograph above; and is the yellow type.
If your machine has a red flap, this is also an option (subject to current stock).
Important: Please examine the photograph and compare it to your old item to be sure they look the same.
The HEPA ones listed here will fit Absolute and De Stijl models of Dyson DC01 that take one filter pad and one circular HEPA filter.
Standard machines are fitted with one without a circular hole. These HEPA ones will NOT fit standard models of Dyson DC01. If you need one without the HEPA hole in, you can find it >>here<<.