New England Vinyl PVC Plastic Fence Post Cap 4" x 4" (White) WHITE Vinyl New England Post Cap Made of Durable, low-maintenance vinyl. For 4" x 4" Vinyl Posts Fits Externally Over a 4" x 4" Vinyl Fence Post Keeping Water etc Out of Your Vinyl Fence Posts Inside Vinyl/PVC Post Cap Dimensions are 4.04" x 4.04" and has Sharp Corner Radius. New England Cap Our Vinyl Fence Post Caps Fit Snugly Over 4" Vinyl Posts. Cap Extends Approx 7/8" Down Side of Post High Quality