An exemplary optical cable comprises a sheath surrounding a cavity and a plurality of modules arranged within the cavity with a filling ratio between 20 and 50%. Exemplary modules include four to twelve optical fibers and a tube surrounding the optical fibers. An exemplary tube has a layered structure including an inner layer of polycarbonate and an outer layer of low friction polymer, such as polyamide and/or fluorinated polymer. An exemplary tube has a ratio between its inner diameter (di) and its outer diameter (do) between 0.45 and 0.55, and its outer layer has a thickness between 0.05 and 0.15 mm. The filling ratio of the module is typically 55% or greater.