An optical fiber comprising: a core region having a refractive index profile Δ(r) and comprising a maximum relative refractive index Δ MAX; an outermost annular cladding region surrounding the core region; a primary coating contacting and surrounding the outer annular cladding region, the primary coating having a Young's modulus of less than 1.0 MPa and a glass transition temperature of less than -25 °C; a secondary coating surrounding the primary coating, the secondary coating having a Young's modulus of greater than 1200 MPa; wherein: the core region comprises a central region extending from the centerline to a radius of 0.8 μm and having a relative refractive index Δ 1 (r), an intermediate region extending from a radius of 0.8 μm to 3 μm having a relative refractive index Δ 2 (r) greater than 0.40% everywhere in the intermediate region and having a maximum difference of the relative refractive index at any two radii within the intermediate region of less than 0.02% and an outer region, at least a part of which comprising a relative refractive index Δ 3 (r) having an alpha (α) shape extending from a radius of 3 μm to 4 μm and having a tangent line drawn tangent to the relative refractive index Δ(r) at a radius corresponding to half the maximum refractive index Δ MAX of the core intersecting the Δ=0% axis at a radius R HH greater than 4.50 μm; the maximum relative refractive index Δ MAX occurs between r = 0 and r = 3 μm; and the maximum relative refractive index Δ MAX is greater than 0.4%, to provide a MAC number of not more than 7.0, a mode field diameter at 1310 nm of between 8.2 and 9.0 μm, a cabled cut-off of less than 1260 nm, a zero dispersion wavelength of less than 1450 nm, and a 20 mm diameter bend loss at 1550 nm of not more than 5.0 dB/m. a core region having a refractive index profile Δ(r) and comprising a maximum relative refractive index Δ MAX; an outermost annular cladding region surrounding the core region; a primary coating contacting and surrounding the outer annular cladding region, the primary coating having a Young's modulus of less than 1.0 MPa and a glass transition temperature of less than -25 °C; a secondary coating surrounding the primary coating, the secondary coating having a Young's modulus of greater than 1200 MPa; wherein: the core region comprises a central region extending from the centerline to a radius of 0.8 μm and having a relative refractive index Δ 1 (r), an intermediate region extending from a radius of 0.8 μm to 3 μm having a relative refractive index Δ 2 (r) greater than 0.40% everywhere in the intermediate region and having a maximum difference of the relative refractive index at any two radii within the intermediate region of less than 0.02% and an outer region, at least a part of which comprising a relative refractive index Δ 3 (r) having an alpha (α) shape extending from a radius of 3 μm to 4 μm and having a tangent line drawn tangent to the relative refractive index Δ(r) at a radius corresponding to half the maximum refractive index Δ MAX of the core intersecting the Δ=0% axis at a radius R HH greater than 4.50 μm; the maximum relative refractive index Δ MAX occurs between r = 0 and r = 3 μm; and the maximum relative refractive index Δ MAX is greater than 0.4%, to provide a MAC number of not more than 7.0, a mode field diameter at 1310 nm of between 8.2 and 9.0 μm, a cabled cut-off of less than 1260 nm, a zero dispersion wavelength of less than 1450 nm, and a 20 mm diameter bend loss at 1550 nm of not more than 5.0 dB/m. the core region comprises a central region extending from the centerline to a radius of 0.8 μm and having a relative refractive index Δ 1 (r), an intermediate region extending from a radius of 0.8 μm to 3 μm having a relative refractive index Δ 2 (r) greater than 0.40% everywhere in the intermediate region and having a maximum difference of the relative refractive index at any two radii within the intermediate region of less than 0.02% and an outer region, at least a part of which comprising a relative refractive index Δ 3 (r) having an alpha (α) shape extending from a radius of 3 μm to 4 μm and having a tangent line drawn tangent to the relative refractive index Δ(r) at a radius corresponding to half the maximum refractive index Δ MAX of the core intersecting the Δ=0% axis at a radius R HH greater than 4.50 μm; the maximum relative refractive index Δ MAX occurs between r = 0 and r = 3 μm; and the maximum relative refractive index Δ MAX is greater than 0.4%, to provide a MAC number of not more than 7.0, a mode field diameter at 1310 nm of between 8.2 and 9.0 μm, a cabled cut-off of less than 1260 nm, a zero dispersion wavelength of less than 1450 nm, and a 20 mm diameter bend loss at 1550 nm of not more than 5.0 dB/m.