The metal motorcycle fork stem base is 1" ball . Suitable for stem tube holes 12mm to 25.4mm in diameter
Package comes with two sizes of metal spacers. Small size spacer fit for tube 12mm to 18.5mm in diameter, Large size spacer fit for tube 18.5mm to 25.4mm in diameter. You can choose one size of the spacers according to the tube diameter for installation. It is not supported to use two spacers of different size at the same time
Wide Fits: the motorcycle fork stem ball base is specially designed to fit into the cylindrical bore wall of fork stems. It fits for YZF R1M/S R6 R6S, for Ninja 400 250 650 1000SX ZX600 Ninja ZX-6RR ZX-14R ZZR, for CBR 250R 300R 400R 650R 600RR 600 F4I, for S1000RR GSX 1300R GSX-R 600 750 1000 , for Panigale V2