KEY RESISTANT STD provides excellent chemical resistance in 1/4 inch trowel epoxy mortar systems, combining a 100% solids chemical resistant bis-F epoxy binder/aggregate mortar base with novolac epoxy seal coats. Key Resistant STD protects concrete and masonry where extreme chemical and thermal protection is required. Key Resistant STD can be installed with an integral cove base for areas requiring seamless wall to floor coatings.