A retractable and temporary use child/pet/security gate or fence or barrier unit manufactured in sections which are joined together by pivoting hinges. In one embodiment the barrier is secured to the non-hinged end of a door and the door frame to prevent children/pets escaping or intruders entering the building. Alternatively, it may be a stair gate or a free standing barrier (Fig. 10). The barrier may be secured in place by locking hooks which engage with eye bolt brackets (12 & 7 Fig. 4, 21 Fig. 12). The panels may be made of steel or wood depending the strength required. When used as a door barrier, two sections 2 could be used one above the other to allow the height of the barrier to be changed and items passed through the door. Also shown is a single barrier section 6 that could be fitted to the bottom of the door 1 to prevent underneath access.