A method of fixing and moisture sealing a telecommunications cable that includes a jacket defining a jacket perimeter having a generally non-circular transverse cross-section with respect to an enclosure includes placing an adapter tube over the jacket, the adapter tube defining a perimeter having a generally circular transverse cross-section and a throughhole having a generally non-circular transverse cross-section; compressing the adapter tube around the jacket with a clamp; placing a portion of the adapter tube within a gel block of the enclosure, the gel block being provided at a location different than the location of the clamp; moisture sealing the adapter tube with sealant material of the gel block; and fixing the adapter tube and the telecommunications cable with respect to the enclosure to oppose pulling forces.