Brimar offers 6 different sizes of letters & numbers to choose from. Each different size offers both a different character height and marker size. The size you choose is determined by two factors. One the room available to put the labels, and two the distance you intend to read the numbers from. Vinyl letters & numbers are stock with either white or safety yellow backgrounds and both have black UV screen printed characters. The vinyl used offers extended durability for outdoors use, up to 7 years. Letters & Numbers are sold by the individual card, each card has a different multiple of characters on them depending on the size you choose.