This listing is: 2.5mm Lowercase Antlia Alphabet Letter Set consisting of Lowercase letters A-Z. This measurement is based on the average size ascender/descender letters. Every letter is not 2.5mm. Please know, based on the actual design of the typeface that the letters i and j are larger measuring approx. 3.5mm. Our Sharper Lines and high rockwell hardness rating make it good for use on stainless steel blanks. Please accept our apologies, the laser engraving on the side of the shank was mismarked at 1.5 mm. The size of the stamp impression is correct.