Abstract:
It is disclosed an optical fiber unit for air-blown installations comprising a number of optical conductors (2), a first layer (3i) of resin material, a second layer (3o) of resin material radially outer to the first layer (3i) of resin material and a sheath (4) of a thermoplastic material, wherein said second layer (3o) of resin material has a Secant Modulus higher than a Secant Modulus of said first layer (3i) of resin material and wherein said sheath (4) of a thermoplastic material is over and in close contact with said second layer (3o) of resin material.