WEATHERABLES Durable White PVC Vinyl External Pyramid Post Cap for A True 4 Inch x 4 Inch Post | Single Pack | AWCP-EXT-4 The External Pyramid cap fits externally on a true 4 in. x 4 in. post | Will NOT fit on a standard 3.5 in. x 3.5 in. wood post | Simple to install | Made in the U.S.A. Manufactured from high quality, durable PVC vinyl | Maintenance Free: Simply slide the External Pyramid Cap onto your post. Set it and forget it. | Limited lifetime warranty Will not fade, discolor or warp | UV Resistant | Water Resistant | Perfect for a fence, deck, or mailbox post | Use clear silicone for outdoor use to secure the cap (optional) Maximum profile dimensions: 4.02 in. x 4.02 in. | Corner Radius: .188 in. | Total height: 1.75 in. | Overall Outside Dimensions: 4.125 in. x 4.125 in. | Color: White Add a simple, clean look to your fence, railing or mailbox post with the 4 in. x 4 in. External Pyramid post cap