Post Wrap/Sleeves - Color Guard Railing.Post Sleeves. Our blank posts sleeves slide over the top of a wood post to provide a low maintenance, finished look. (Available in White, Tan, and Clay). 4″ x 4″ Blank Post Sleeve (Available lengths: 38″, 44″, 50″, 96″, 108″, 120″). 5×5 Blank Post Sleeve ( Available lengths: 108″ ). 6×6 Blank Post Sleeve.