THERMALITE SEAT POST - Features: Thermalite is proprietary material made with Nylon 66 base w/ 50% long glass fiber infusion. Thermalite posts are 30% lighter than the current Alloy posts on the market. - Size: 25.4mm X 150mm length. - Colors: Black, or White and Limited Edition colors. - Weight: 2.8oz. (150mm length).