Precision molded white plastic letters in Helvetica or Roman font styles. These changeable plastic letters are universal and will work with other manufacturer's changeable letter boards and directory boards. These letter board replacement letters and numbers feature a single tab at the bottom of each character so they will fit any manufacturer's letter boards. Our changeable plastic letters and numbers are only available in white. The white plastic letters and numbers are in a classic Helvetica (Serif) of Roman (Sans Serif) font. Our changeable plastic letters are available in either boxed sets or in sprue sets. White plastic letters in a sprue set means that the letters and numbers are still attached to each other with little tabs that can easily be broken apart. This is not most convenient way to purchase if you need a lot of letters but it can be cheaper for you to purchase this way if you need a lot of a specific letter or number instead of purchasing entire sets of changeable plastic letters. The Helvetica font changeable plastic letters are available in five sizes of ½"", 3/4"", 1"", 2"" and 3"" heights. The ½"", 3/4"", & 1"" come in a boxed set of at least 408 characters and the 2"" & 3"" sizes come in a boxed set of at least 290 characters. The Roman font changeable plastic letters are available in 3 sizes 1"" 2"" & 3"" They are also available in sets of 408 characters (1 inch) and 290 characters (2 & 3 inch) The letter board replacement letters that are in the sprue sets are available in the same sizes but with only 145 characters.