An enclosure (20, 220) comprising: a housing (22, 222) defining a sealing unit opening (36, 230) having an outer end; a sealing unit (48, 42a, 232) that mounts within the sealing unit opening (36, 230), the sealing unit (48, 42a, 232) including a sealant arrangement (52, 236) that defines a plurality of cable ports, the sealing arrangement (52, 236) also being configured for providing a peripheral seal between the housing (22, 222) and the sealing unit (48, 42a, 232), the sealing unit (48, 42a, 232) further including an actuation arrangement (56, 238) for pressurizing the sealant arrangement (52, 236) within the sealing unit opening (36, 230), the actuation arrangement (56, 238) including inner and outer pressurization structures (160, 160a, 162) between which the sealant arrangement (56, 236) is positioned, the actuation arrangement (56, 238) also including a spring for applying a pressurization force that causes the sealant arrangement (56, 238) to be pressurized between the inner and outer pressurization structures (160, 160a, 162) when the actuation arrangement (56, 238) is actuated, the sealing unit (48, 42a, 232) being mounted in the sealing unit opening (36, 230) by inserting the sealing unit (48, 42a, 232) through the outer end of the sealing unit opening (36, 230), and the sealing unit (48, 42a, 232) being removable from the sealing unit opening (36, 230) through the outer end of the sealing unit opening (36, 230); and a cable anchoring location coupled to the inner pressurization structure (160, 160a); the enclosure being characterized by means of: a fastening arrangement (55, 155a) for fastening the inner pressurization structure (160, 160a) to the housing to retain the sealing unit (48, 42a, 232) in the sealing unit opening (36, 230), wherein the fastening arrangement (55, 155a) can be unfastened to allow the sealing unit (48, 42a, 232) to be removed from the sealing unit opening (36, 230) through the outer end of the sealing unit opening (36, 230). a housing (22, 222) defining a sealing unit opening (36, 230) having an outer end; a sealing unit (48, 42a, 232) that mounts within the sealing unit opening (36, 230), the sealing unit (48, 42a, 232) including a sealant arrangement (52, 236) that defines a plurality of cable ports, the sealing arrangement (52, 236) also being configured for providing a peripheral seal between the housing (22, 222) and the sealing unit (48, 42a, 232), the sealing unit (48, 42a, 232) further including an actuation arrangement (56, 238) for pressurizing the sealant arrangement (52, 236) within the sealing unit opening (36, 230), the actuation arrangement (56, 238) including inner and outer pressurization structures (160, 160a, 162) between which the sealant arrangement (56, 236) is positioned, the actuation arrangement (56, 238) also including a spring for applying a pressurization force that causes the sealant arrangement (56, 238) to be pressurized between the inner and outer pressurization structures (160, 160a, 162) when the actuation arrangement (56, 238) is actuated, the sealing unit (48, 42a, 232) being mounted in the sealing unit opening (36, 230) by inserting the sealing unit (48, 42a, 232) through the outer end of the sealing unit opening (36, 230), and the sealing unit (48, 42a, 232) being removable from the sealing unit opening (36, 230) through the outer end of the sealing unit opening (36, 230); and a cable anchoring location coupled to the inner pressurization structure (160, 160a); the enclosure being characterized by means of: a fastening arrangement (55, 155a) for fastening the inner pressurization structure (160, 160a) to the housing to retain the sealing unit (48, 42a, 232) in the sealing unit opening (36, 230), wherein the fastening arrangement (55, 155a) can be unfastened to allow the sealing unit (48, 42a, 232) to be removed from the sealing unit opening (36, 230) through the outer end of the sealing unit opening (36, 230). a fastening arrangement (55, 155a) for fastening the inner pressurization structure (160, 160a) to the housing to retain the sealing unit (48, 42a, 232) in the sealing unit opening (36, 230), wherein the fastening arrangement (55, 155a) can be unfastened to allow the sealing unit (48, 42a, 232) to be removed from the sealing unit opening (36, 230) through the outer end of the sealing unit opening (36, 230).