Easily cover your wood 4 x 4's with these vinyl post sleeves. Will slide over a treated 4 x 4. Multiple sizes available. 3 different colors. Accessories available! Treated wood 4" x 4" post are roughly 3.5"x 3.5" when dry. Inside Vinyl 4" x 4" Sleeve inside dimensions are roughly 3.750" x 3.750".