Fret gut is treble gut that has some flaw in it that make it unsuitable as a musical string. The length of the strands is 46", (117 cm). You can purchase fretgut in individual lengths, or you can purchaes a FretPack for viol, or a FretPack for lute. The Voil Fretpack contains one each: 1.10mm, 1.05mm, 1.00mm, .95mm, and .90mm. The Lute FretPack contains on each: 1.00mm, .95mm, .90mm, .85mm, .80mm, .75mm, .70mm, and .65mm.