Ronstan Narrow Forged Saddle with Ferrule Eye The size 4 fitting is the RF 499. Holes centers is 27.7mm Hole Diamemter is 9.4mm Fitting width is 4.9mm The size 5 fitting is the RF 1058. Holes centers is 36.6mm Hole Diamemter is 11.7mm Fitting width is 5.8mm Read more