The mosaic is based on building board. It is totaly weatherproof. You can glue it directly onto the wall or can ask with hanging device. Please let me know your choice and your house number in the "Notes to Seller". Measuring 24 cm x 18cm x 2 cm. With one digit. Each more digit plus about 10 cm. Above 3 digits the numbers will be smaller, otherwise the table would be too big.