Unit insignia for the 337th Test and Evaluation Squadron, 53rd Wing, Air Combat Command, US Air Force.
Eglin AFB Website (<a rel="nofollow" class="external free" href="http://www.eglin.af.mil/53wg/53d_teg.htm">http://www.eglin.af.mil/53wg/53d_teg.htm</a>) (old link)