Molded from actual rocks, these incredibly lifelike address boulders look and feel natural since they''''re manufactured from cast stone--not fiberglass or polyurethane--to withstand 9,000 psi (pounds per square inch) of pressure and freeze-thaw conditions. The replicas of 500-1,000 lb. boulders are hollow, open at the bottom and weigh 50-60 lbs. Each model features a hand-chiseled recess and 13-1/2" (W) x 7-3/4" (H) rustproof aluminum plaque with your choice of up to seven characters in gold letters on a black background with ivy borders. Anti-theft metal eye bolt and easy instructions included.