The G Hinge.
Panty lines are a thing of the past with this nearly invisible seat hinge. Dont weld on that frame like I did..... simple hinge that bolts on to those funny little holes in your Rigid Panhead or Knucklehead frame. Fits a little higher on Knuckle frames due to geometry of original castings. Its not really a hinge, more of a pivot that is hidden as much as possible.
Aluminum with a pressed steel pin.
Available in raw soft tumbled and hard wet polished.
Comes with parkerized hardware.