Cannot detect iPhone generation- why doesn't this work?

I have been having a heck of a time trying to detect which generation of iPad is being used. I have found many different pages with solutions that must have been deprecated as none of them seem to work. This is what I have now which compiles OK but doesn't seem to do anything. Why doesn't this work?

  #pragma strict
         var Props_a : GameObject; 
         static var generation: iPhoneGeneration;
         
         function Start () {
         if( generation == iPhoneGeneration.iPad1Gen ){
                 Destroy(Props_a);
             
         }}