Ohlins 2-way adjustable rear shock and hydraulic preload for a 2003-2004 ZX6R / ZX6RR. The top is stamped with KA9400, but I believe this P/N was an odd-ball (used only for a very short period between 00-02 shocks and 03-04 shocks). I believe the normal P/N for this is KA301; mine resembles a KA301 in every way. I had used on on an 03 ZX6R and 04 ZX6RR. The spring is 01091-34/100 L104 (OEM spring). I believe this is designed for 180-200lb rider, but you'll have to confirm.
This shock was regularly serviced by GMD Computrack, most recently on Feb 28 2017. It has zero miles since the refresh. It's clean and ready to go. I'll include the a copy of the service sheet from GMD Computrack. Asking $600.