Good used radiator to suit K100RS 16 v; K1; K1100 models. These will fit K75RT; K100 8v models as well but are narrower than the 8v bikes. The core is 34mm wide.
You may need to put another thermostat in them. Thermostat is not covered under Warranty. It is there to fill the hole.
These will most likely not come with the rubber where the bolt goes through to the frame. Most of the time these are damaged so you will need to replace with the one from your radiator.
Photo is a representation only and may not be the one shipped.