Magnaflux Zyglo ZL-56 Penetrant - Level 4Magnaflux ZL 56 Level 4 Water Washable Fluorescent Penetrant Experience the ultimate in defect detection with the ultra high sensitivity ZL 56 fluorescent penetrant. This Level 4 penetrant is specifically formulated for safe use on a variety of alloys, including aluminum, steel, nickel, and titanium, making it ideal for engineering and aerospace applications. Designed for non porous and highly machined components, ZL 56 ensures exceptional performance