Abstract: A pair of spaced elongate primary security members extend in a first direction, and each has a plurality of longitudinally spaced openings. The ends of a plurality of elongate secondary security members, extending in a second direction which is transverse to the first direction, are located in aligned openings in the primary security members. The ends of the secondary security members are thereby held captive in the primary security members. The secondary security members span a space between the primary security members, and the secondary security members are thus spaced apart from one another. A tertiary security member supports the secondary security members between the primary security members. An electrically operable burglar protection system, having an alarm, is connected to the security members.