Stainless Steel Clampco T-Bolt Clamp.
This 3.50" Clamp is for 3.25" pipe connections.
Comes with Nylon lock nuts to prevent the nut from loosening.
Some of the largest manufacturers use Clampco, why?
Because they expect the highest quality!
Caterpillar / Cummins / Detroit Diesel / Freightliner / Mack Trucks / Ford / Volvo.... just to name a few.