An optical termination enclosure (100) defines ruggedized adapters at output ports (132); a cable entry port (105) through which an input cable can enter the enclosure; and a sealing arrangement (150) disposed at the cable entry port (105) to seal around the input cable. The sealing arrangement (150) includes a gasket block arrangement (151) defining at least a first cable aperture (108) sized to receive an optical cable; and a retention arrangement (160) to activate the gasket block arrangement (151). The retention arrangement (160) includes a wedge-shaped body (161) and a gel-type sealing member (180).