Made of Sterling's exclusive Vikrell material with swirl gloss finish. Vikrell is a sheet molded compound that is solid color throughout and stronger than fiberglass. Must be used with our base and end walls. Base Model No. 62021100-0 (SKU 400784) and end walls Model No. 62015100-0 (SKU 473812). Sterling Vikrell shower systems assemble with a tongue and groove system that minimizes the need for caulk. Sterling Vikrell fixtures are backed by a 10 year consumer warranty.