Used on kc-135 nlg strut. static seal assembly nonstandard gland size 5.520/5.522 bore dia; 5.028/5.026 groove dia; 0.408/0.413 groove width mfg material turel bak o-ring equivalent to mil-p-25732 mfg material turcon 19 ptfe back-upring operating fluid per mil-h-5606