Lumen Nails come in both the large head, and small head. Also notice some nails have a "thick" lettering, and some have a "thin" lettering. Lumen nails are found on poles with street lights and the lumens reflect the size of the bulb. There is a 2500 Lumen that is a new variation. The Diameter is slightly smaller than the known Lumen nails. Also the numbers and letters are more defined. These Lumens were found in Florida by Byrne Mollohan