If your machine is leaking from the area around the coffee filter this is the part you need.
Ensure that you are purchasing the correct part as there are three versions of the Breville gasket. Here is a link to the 54mm version and the 50mm version
Please check your machine series number before purchasing
54mm Steam Ring fits:
BES870XL & BES860XL,
the Infuser™, BES840XL,