This is a brand new foam seal gasket for the cyclone on the Dyson DC25 and the DC18.

This is the gasket seal that is accessed by splitting the cyclone. Sometimes these degrade and cause cyclone leakage and thus suction loss. 

Sometimes when you split a cyclone for cleaning, the old one is unusable rendering the cyclone effectively scrap.  However, we now sell the replacement cyclone gasket seals here.  

This gasket ONLY fits the DC18 and the DC25. 

So please do not buy it for another model or if you are unsure that your machine is a DC18 or a DC25.