A port sealing device for receiving an optical cable when passing through a peripheral wall of a termination box, comprising: - a body configured to switch between an open and a closed configuration, said body defining a cable pass-through channel extending along an axial direction (X-X) when said body is the in closed configuration, - sealing arrays (30a, 30b, 30c) arranged in the channel, each sealing array (30a, 30b, 30c) being arranged in the channel along an annular direction (α) around said axial direction (X-X) in the closed configuration, each sealing array (30a, 30b, 30c) being spaced apart from an adjacent sealing array (30a, 30b, 30c) along said axial direction (X-X) and comprising sealing elements mutually spaced apart along the annular direction (α) when in the closed configuration, when the body is in the open configuration the sealing elements of each sealing array (30a, 30b, 30c) are arranged mutually adjacent along a longitudinal direction (Y-Y) and each sealing array (30a, 30b, 30c) is spaced apart from an adjacent sealing array (30a, 30b, 30c) along a transverse direction (X'-X') perpendicular to said longitudinal direction (Y-Y),the sealing elements of a sealing array (30a, 30b, 30c) are arranged in the channel with a pattern different from the pattern of the sealing elements of an adjacent sealing array (30a, 30b, 30c) wherein - said body has two end portions with respective connecting portions and a joining portion joining the two end portions, such that in the closed configuration the two end portions are connected through removable coupling of the two connecting portions and in the open configuration the two end portions of the body are spaced apart along the longitudinal direction (Y-Y); and wherein - the body is made of flexible material and is configured to be bent from the longitudinal direction (Y-Y) to the annular direction (α) coupling the two end portions passing from the open configuration to the closed configuration in order to define the channel such that the joining portion surrounds the channel and extends along the annular direction (α) in the closed configuration while defining openings of the channel for the passage of the optical cable, the joining portion being configured to flex between the open and the closed configuration. - a body configured to switch between an open and a closed configuration, said body defining a cable pass-through channel extending along an axial direction (X-X) when said body is the in closed configuration, - sealing arrays (30a, 30b, 30c) arranged in the channel, each sealing array (30a, 30b, 30c) being arranged in the channel along an annular direction (α) around said axial direction (X-X) in the closed configuration, each sealing array (30a, 30b, 30c) being spaced apart from an adjacent sealing array (30a, 30b, 30c) along said axial direction (X-X) and comprising sealing elements mutually spaced apart along the annular direction (α) when in the closed configuration, when the body is in the open configuration the sealing elements of each sealing array (30a, 30b, 30c) are arranged mutually adjacent along a longitudinal direction (Y-Y) and each sealing array (30a, 30b, 30c) is spaced apart from an adjacent sealing array (30a, 30b, 30c) along a transverse direction (X'-X') perpendicular to said longitudinal direction (Y-Y),the sealing elements of a sealing array (30a, 30b, 30c) are arranged in the channel with a pattern different from the pattern of the sealing elements of an adjacent sealing array (30a, 30b, 30c) wherein - said body has two end portions with respective connecting portions and a joining portion joining the two end portions, such that in the closed configuration the two end portions are connected through removable coupling of the two connecting portions and in the open configuration the two end portions of the body are spaced apart along the longitudinal direction (Y-Y); and wherein - the body is made of flexible material and is configured to be bent from the longitudinal direction (Y-Y) to the annular direction (α) coupling the two end portions passing from the open configuration to the closed configuration in order to define the channel such that the joining portion surrounds the channel and extends along the annular direction (α) in the closed configuration while defining openings of the channel for the passage of the optical cable, the joining portion being configured to flex between the open and the closed configuration.