Mersen's Fabfin finned heatsink family comprises the MF, AF, DF, and FF designations, which respectively provide fin center-to-center (cc) pitch of 3.43, 5.49, 6.86 and 8.51mm; or in terms of fins-per-inch (fpi), 7.4, 4.6, 3.7 and 3.0. The maximum fin height-to-gap ratios are respectively MF 22:1, AF 30:1, DF 27:1, and FF 20:1. Mersen highest ratio heatsink is the Hollow Fin, which uses the DF baseplate, and it has a maximum fin height-to-gap ratio of 48:1. Comparable, state-of-the-art single- piece extrusions can presently achieve max fin ratios only as high as about 15:1. Mersen presently uses extruded fins, which are 1.04, 1.52 and 2.4mm in thickness.