Kerscher adjustable struts that have full range adjustable lower spring platforms. They come with Koni yellow bottom adjustable inserts. The earlier version had a helper spring but mine are the most recent, 80mm single, progressivley wound Eibach springs. Quality is amazing and the springrate feels perfect. Also uses VW Golf/951 strut bolts, one of which has eccentric washers for camber adjustment. Uses stock top bearing.
Worth every penny/cent/pfenig.
TUV approved which is the best bit
Matt
Pic is of the earlier 02/03 strut from the M7 site:
