LATICRETE SpectraLOCK PRO Epoxy Grout Part A&B Liquids. (ONLY) REQUIRES 4 PART C 9lb LATICRETE SpectraLOCK PRO Epoxy Grout is the finest grout available. Whether a residential bathroom or a light commercial floor, LATICRETE SpectraLOCK PRO Grout provides unmatched performance with incredible ease of use.LATICRETE SpectraLOCK PRO Grout is a patented, highperformance epoxy grout that offers color uniformity, durability and stain resistance with extraordinary ease of use.