Durable White PVC Vinyl Dome Ball Post Cap For A True 4 Inch X 4 Inch Post | Single Pack | AWCP-BALL-4 The Dome Ball Cap fits externally on a true 4 in. x 4 in. post | Simple to install | Made in the U.S.A. Manufactured from premium quality, durable PVC vinyl | Maintenance Free: Simply slide the Dome Ball 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 (not included) for outdoor use to secure the cap (optional) Maximum profile dimensions: 4.025 in. x 4.025 in. | Corner radius: .125 in. | Total height: 5 in. | Extends .680 in. over the post profile | Color: White Enhance your vinyl posts with the 4 in. x 4 in. Dome Ball Cap | Dome Diameter: 3.818