What is the instalation hole size ..and the on center dimensions

The mounting hole diameter for the spout part need to be at least 22mm (0.87\") and for the handle parts need to be at least 28mm (1.11\"). If there are already holes but any one is not big enough, we suggest drilling the hole diameter in 35mm (1.38\") if the size of your tub deck allows, which is an international standard size. For widespread faucets, there will be two 200mm (7.87\") flexible hoses included for connection, so the distance between the spout and handles is adjustable.