These brand new U-bolts are 100% made in Australia and are made from 304 stainless steel. 316 Stainless washers & Nyloc nuts included. These were custom made to hold fishing rod holders to 2.5 inch bull bars, but their small diameter will suit many other uses. 
 
These bolts will fit  ø69 maximum round bars and are diameter 6mm with M6 threads. 
 
Set includes : 2x U-bolts, 4x washers, & 4x nuts.