The spigot end that fits into your head is 1

giving you two center-to-center measurements

Size: 5/16 inside diameter x 3/4 inch length

just use the plate bolts to affix this bracket to the plate mount

you can trust in Pazon's reputation for quality and our thorough fitment guides

Weld-On Upper Fender Mount Tab for Flat and Trailer Motorcycle Fenders Length_.75" The spigot end that fitsThis tab was designed as an upper mount for your motorcycle rear fender, though it can be used universally to mount anything you like. It is 1 4 inch thick mild steel and has a 90 degree bend and a 5 16 inch diameter hole in it. This will work well with most any flat or trailer fender custom rear motorcycle fender and saves a lot of time and hassle in the garage. Check out the Weld On Lower Fender Mount Tab, DIY Fender Strut Kit and DIY Sissy Bar Kits