"18 IN. W, 18 IN. H; 5 HOLES: 0.50IN. DIA, 0.75 IN. DIA, 1.25 IN. DIA, 3.50 IN. LG. BY 0.50 IN H, AND 3.50 IN.-LG. BY 0.10 IN. H; O/A 1.75 IN. DP; INCL FOAMING ADHESIVE, HONEYCOMB, GR/EPSKIN (0.125 IN.); INDUCED LACK OF BONDAT CENTER CORE TO FOAM; SERD NO. 1627"