The Trex Transcend Railing system reflects a thoughtful design where appearance and quality are paramount. Made with Fibrex material, the Transcend Post Sleeve naturally goes with Transcend Railings. 6 in. x 6 in. x 39 in. Classic White Post Sleeve looks like painted wood and they compliment any traditional architecture. Classic White Post Sleeve slides over a 4 in. x 4 in. pressure treated post.