KW Suspension - Ventilation Disc

[Ads17]

I have KW DCC Coilovers fitted, the rear dampers have a plastic token which sits loose at the bottom of the piston apparently called a Ventilation Disc according to the KW spare parts list. I believe this to be vibrating when driving and the source of the noise I am hearing in the cabin.

Before I start messing about with it does anyone know what purpose it serves as I can't find any info online?

[CarsOrBikes]

don't know about the KW's but I have Koni Sport adjustable dampers on my classic Mini that have exactly this type of disc, it's only purpose is to block the type of hole you can see visible in your pic that the Koni's also have (x2), which is used by the top dust cover that contains two pegs that locate in the holes to adjust the damper, like a key way, so one removes the disc hence its cut out so you can lift one end and slide it over the damper rod, lower the top and set the damper, then extend it and refit the disc. Like I say, no idea if for a similar purpose on yours although it looks familiar hence reply ;O)