Accu-Flo Dyne Pens work just like magic markers, so users can quickly draw a line on the material. Accu-Flo Dyne Pens produce an even and consistent lay-down of the dyne fluid to insure accurate, repeatable dyne readings. Accu-Flo Dyne Pens are available in even dyne levels ranging from 32 to 58 dynes/cm.