3.5 inch (I.D.) U bolt c/w washers
M8 thread. Our M8 stainless wing nuts fit these clamps (and many others).
P&P is cheaper for this item if you phone the order through !
This is a very adaptable product because our 3.5in sledges (available separately) fit, so it can be used in a large variety of ways.
Pole on a post
Available with plain or Nyloc nuts.