The use of unsplit lamb gut, besides being closer to the historical reality of the string makers of the past, has also led to strings with unexpected superior acoustical and mechanical properties, as compared to those produced with gut strips. The HU type strings have a surface that has been smoothened only the minimum needed to guarantee that the string is not false; the string is then slightly oiled.
Standard length is 120 cm up to diameters of 1.90 mm. Starting from a diameter of 2.00 mm, the standard length changes to 180 mm only.

Are you maybe thinking about historical gauges for bowed instruments?
SKUGaugeLengthPriceBuyhf:att:pa_diametrohf:att:pa_lunghezza
38HU0.38 mm120 cm4.60 + VAT
0-38-mm-en120-cm-en
40HU0.4 mm120 cm4.60 + VAT
0-4-mm-en120-cm-en
42HU0.42 mm120 cm4.60 + VAT
0-42-mm-en120-cm-en
44HU0.44 mm120 cm4.60 + VAT
0-44-mm-en120-cm-en
46HU0.46 mm120 cm5.00 + VAT
0-46-mm-en120-cm-en
48HU0.48 mm120 cm5.00 + VAT
0-48-mm-en120-cm-en
50HU0.5 mm120 cm5.00 + VAT
0-5-mm-en120-cm-en
52HU0.52 mm120 cm5.00 + VAT
0-52-mm-en120-cm-en
54HU0.54 mm120 cm5.90 + VAT
0-54-mm-en120-cm-en
56HU0.56 mm120 cm5.90 + VAT
0-56-mm-en120-cm-en
58HU0.58 mm120 cm5.90 + VAT
0-58-mm-en120-cm-en
60HU0.6 mm120 cm6.20 + VAT
0-6-mm-en120-cm-en
62HU0.62 mm120 cm6.20 + VAT
0-62-mm-en120-cm-en
64HU0.64 mm120 cm7.70 + VAT
0-64-mm-en120-cm-en
66HU0.66 mm120 cm7.70 + VAT
0-66-mm-en120-cm-en
68HU0.68 mm120 cm7.70 + VAT
0-68-mm-en120-cm-en
70HU0.7 mm120 cm7.70 + VAT
0-7-mm-en120-cm-en
73HU0.73 mm120 cm7.70 + VAT
0-73-mm-en120-cm-en
76HU0.76 mm120 cm9.20 + VAT
0-76-mm-en120-cm-en
79HU0.79 mm120 cm9.20 + VAT
0-79-mm-en120-cm-en
82HU0.82 mm120 cm9.20 + VAT
0-82-mm-en120-cm-en
85HU0.85 mm120 cm9.20 + VAT
0-85-mm-en120-cm-en
88HU0.88 mm120 cm9.20 + VAT
0-88-mm-en120-cm-en
91HU0.91 mm120 cm11.60 + VAT
0-91-mm-en120-cm-en
94HU0.94 mm120 cm11.60 + VAT
0-94-mm-en120-cm-en
97HU0.97 mm120 cm11.60 + VAT
0-97-mm-en120-cm-en
100HU1 mm120 cm11.60 + VAT
1-mm-en120-cm-en
104HU1.04 mm120 cm11.60 + VAT
1-04-mm-en120-cm-en
108HU1.08 mm120 cm11.60 + VAT
1-08-mm-en120-cm-en
112HU1.12 mm120 cm14.90 + VAT
1-12-mm-en120-cm-en
116HU1.16 mm120 cm14.90 + VAT
1-16-mm-en120-cm-en
120HU1.2 mm120 cm16.80 + VAT
1-2-mm-en120-cm-en
124HU1.24 mm120 cm16.80 + VAT
1-24-mm-en120-cm-en
128HU1.28 mm120 cm16.80 + VAT
1-28-mm-en120-cm-en
132HU1.32 mm120 cm16.80 + VAT
1-32-mm-en120-cm-en
136HU1.36 mm120 cm16.80 + VAT
1-36-mm-en120-cm-en
140HU1.4 mm120 cm19.10 + VAT
1-4-mm-en120-cm-en
145HU1.45 mm120 cm19.10 + VAT
1-45-mm-en120-cm-en
150HU1.5 mm120 cm19.10 + VAT
1-5-mm-en120-cm-en
155HU1.55 mm120 cm19.10 + VAT
1-55-mm-en120-cm-en
160HU1.6 mm120 cm20.90 + VAT
1-6-mm-en120-cm-en
165HU1.65 mm120 cm20.90 + VAT
1-65-mm-en120-cm-en
170HU1.7 mm120 cm20.90 + VAT
1-7-mm-en120-cm-en
180HU1.8 mm120 cm24.00 + VAT
1-8-mm-en120-cm-en
190HU1.9 mm120 cm26.90 + VAT
1-9-mm-en120-cm-en
200HU1802 mm180 cm53.80 + VAT
2-mm-en180-cm-en
210HU1802.1 mm180 cm62.50 + VAT
2-1-mm-en180-cm-en
220HU1802.2 mm180 cm62.50 + VAT
2-2-mm-en180-cm-en
230HU1802.3 mm180 cm62.50 + VAT
2-3-mm-en180-cm-en
240HU1802.4 mm180 cm68.70 + VAT
2-4-mm-en180-cm-en
250HU1802.5 mm180 cm68.70 + VAT
2-5-mm-en180-cm-en
260HU1802.6 mm180 cm68.70 + VAT
2-6-mm-en180-cm-en
280HU1802.8 mm180 cm86.00 + VAT
2-8-mm-en180-cm-en
300HU1803 mm180 cm86.00 + VAT
3-mm-en180-cm-en
320HU1803.2 mm180 cm89.70 + VAT
3-2-mm-en180-cm-en
340HU1803.4 mm180 cm89.70 + VAT
3-4-mm-en180-cm-en
400HU1804 mm180 cm94.10 + VAT
4-mm-en180-cm-en
420HU1804.2 mm180 cm98.90 + VAT
4-2-mm-en180-cm-en
440HU1804.4 mm180 cm103.60 + VAT
4-4-mm-en180-cm-en
460HU1804.6 mm180 cm110.60 + VAT
4-6-mm-en180-cm-en
200HU2 mm120 cm26.90 + VAT
2-mm-en120-cm-en