Post Shields (3.5" x 3.5" x 6" High White: Protects Mailbox and Fence Posts from Grass Trimmer Damage. Post Shields enhance the appearance of your property by decorating, concealing and protecting your deck, pergola, fence, and mailbox posts from lawn maintenance equipment! Post Shields look great and are easy to install. Simply slide the shields together around the post and increase your property's curb appeal. Made of durable plastic, Post Shields protect your property and improve the appearance of your home or office!