Hillman 3 In. Black & Silver Mylar - Wide Style - Reflective - P features reflective letters that are three inches and larger, designed to meet US Coast Guard and 911 requirements for boat registration posting. These versatile letters can be used on houses, mailboxes, mailbox posts, jet skis, and boats, providing clear and durable identification with a striking black and silver mylar finish. This product combines functionality with compliance, making it an i choice for various outdoor labeling needs.