Durable White PVC Vinyl External Pyramid Post Cap For A True 3.5 Inch x 3.5 Inch Post | Single Pack | AWCP-EXT-3.5 The External Pyramid cap fits externally on a true 3.5 in. x 3.5 in. post | Will also fit on a standard 4x4 wood post (usually measure to 3.5 in.x 3.5 in.) | Simple to install | Made in the U.S.A. Manufactured from high quality, durable PVC vinyl | Will not fade, discolor or warp | UV Resistant | Water Resistant | Limited lifetime warranty Perfect for a fence, deck, or mailbox post | Maintenance Free: Simply slide the External Pyramid cap onto your post. Set it and forget it. | Use clear silicone (not included) for outdoor use to secure the cap (optional) Maximum profile dimensions: 3.510 in. x 3.510 in. | Corner Radius: .125 in. | Total height: 1.42 in. | Overall Outside Dimensions: 3.625 in. x 3.625 in. | Color: white Add a simple, clean look to your fence, railing or mailbox post with the 3.5 in. x 3.5 in. External Pyramid post cap