Spacer apparatus for the Vanagon swivel. This is a 7/16-20 x 1 1/2 Grade 8 bolt with the Vanagon swivel washer, a 7/16 washer, a 7/16-20 nut, a 1/2 lock washer, and another 7/16 washer. Yes, the bolt really is 7/16-20 (I was just as surprised as you are).