Fluorescent Penetrant MET-L-CHEK FP-97A (M) – Sensitivity 4 – an ultra-high sensitivity penetrant that is approved for use on fracture critical rotating turbine components by Boeing BSS 7039 & BAC 20-20-0, Pratt & Whitney FPM PMC #4353-AG, General Electric Aircraft Engines 70-32-02 & Gas Turbines LM6000 PC 11, RollsRoyce RPS-702-7. Used with either lipophilic E-57 (Method B) or hydrophilic E-58D (Method D) emulsifiers.