Spotcheck SKL-SP1 Penetrant Part Number and Container Size: F01001 – 1 LTR F01002 – Aerosol Applications: Welds, Forgings, Pressure Vessels, Castings, General Metal Work, Leak Testing, Power Plant, Construction. Classification: Type 2, Method B, C or D Temperature: SKL-SP1 should be used at temperatures between 40° F to 125° F.