Used on c-17a aircraft. seal assembly, closeout item is round with outside diameter of 15.74; has eight .500 holes; is made from the following materials:insert is aluminum per qq-a-250/4 temp T3; core is sheet silicone rubber cellular per dms 1980 grade 1-soft class 1; cover is cloth polyester knitted mesh per dms 2356 type 2, class 4; liner is silicone elastomer per dms 2221 type 1 grade 50 light gray