Curbblocks – The Original Polystyrene *Patent Protected* Prefabricated shower curb. The only prefabricated curb on the market that accepts and integrates a traditional shower pan / liner. Provides the quickest and easiest way to build a curb. Pre – sloped on top surface to shed any moisture back into wet area. Easily cut to fit any situation. Alignment strip Included to ensure ease of installation.