The flat post cap features beveled edges and a durable urethane construction. As part of our selection of balustrade accessories, the flat post cap gives the balustrade a refined and customized appearance. This post cap is designed for use with the 5 in. balustrade system, a system that maintains a sleek profile while offering more detail and character than the standard railing. The post cap is traditional in appearance, but precision-molded in urethane. This rigid, high-density material is excellent for the crafting of balustrades that remain beautiful. Urethane balustrade components feature a unique closed cell structure that prevents the excessive levels of moisture absorption that can lead to cracking and decay. Material: Resin.