While it would appear, at first glance, that the back-plates for the dashboard Heuers are all just about the same, a closer examination of the subject reveals that there are significant differences between the various back-plates.  First, let's begin with the specifications that are identical for all the back-plates (using the single back-plate for this discussion).  Specifications that are common for all the backplates are as follows: <UL><LI>they are square, with a size of 2-1/4 inches by 2-1/4 inches</LI>
<LI>they are made of metal</LI>
<LI>they have a circular cut-out so that the timepiece is set into the plate</LI>
<LI>they have two sets of holes -- a set of three small holes to attach the timepiece to the plate and a set of holes to attach the back-plate to the dashboard</LI></UL>
<p>
Having now described the common specifications, scroll to the text below the photographs to read about the fascinating differences between the various Heuer back-plates.<p>