I thought this was either a Givi / Kappa Luggage Arms set up for the Brand New GIVI Top Box.... But, have discovered it is an actual KAWASAKI branded oe item.  It is the standard type Givi  version 4100 model and has fixings, although you will need to use the original bolts from the rear pillion hand grab bars. It is a little bit fussy with the cage to place under the rear wheel arch for this set up.  There is a Givi Top Box Mount plate with the hard steel plate below, you may be able to modify it for other brands but, that is your choice.  In a Great solid used condition with slight marks here or there from use.   You cannot use with the oe pannier set up as i found out.... it could be dangerous to use with oe panniers and there could be more pressure on the original sub-frame bolts snapping if used as a 3 box set up system.  Shad do a 3 Piece set up for the Z1000SX but it is quite pricey (better to buy a Kawasaki with the set up already in place).  A Big solid set up and ideal for those riders desiring the useful Top-Box addition to their own bike. The Givi mounting plates are solidly secure in place as shown, the bolts could do with cutting down a bit if that fussy.