Magnaflux Spotcheck SKL-4C, Water based Visible/Fluorescent Penetrant Magnaflux| 3746 Magnaflux Spotcheck SKL-4C, Water based Visible/Fluorescent Penetrant Print Magnaflux| 3746 Magnaflux Spotcheck SKL-4C, Water based Visible/Fluorescent Penetrant Water-based, water washable penetrant, light red in daylight and fluorescent orange under UV light. Specifically designed for chemically sensitive plastics, and for leak detection. Use in conjunction with SKD-S2 or ZP-5B developers. Options: MGSKL4C-1: SKL-4C, 5gal (18.9L) pail. MGSKL4C: SKL-4C, 55gal (208L) drum. Request for information