SHELL Rotella Fully Formulated 50/50 Antifreeze w/SCA is a conventional, single-phase, ethylene glycol based heavy-duty diesel engine coolant with silicate, nitrite and molybdate. It already contains the initial dose of supplemental coolant additives (SCA?s) and is ready for use in initial fill, flush and fill, and top-up applications. Compatible with commercially available SCA?s. Commercially available test strips or a test tool can be used with this product to determine when additional SCA?s must be added.