The 05604 is an expanding rubber block style anchor point that mounts into the stake pocket hole of some truck beds.
The relaxed rubber block size is 2.02” x 1.21”……it will expand at least .25” larger (expands to approx. 2.25” x 1.46”) when the anchor eye is tightened.
The stake pocket opening should be close to the relaxed block size so that it will secure to the truck bed rail properly.