An enclosure (10) including at least one elongate, substantially planar wall member (11) and at least one post member (12) having at least two edge channel (13), each at least one wall member (11) having an edge which fits into at least one edge channel, the edge of the wall member (11) having a plurality of spaced apart projections (14) which extend from each side of the wall member (11), the edge channel (13) having a pair of spaced apart, substantially parallel flanges (15) between which the edge of a wall member (11) is received and an abutment shoulder (17) on at least one of the substantially parallel flanges (15) in order to engage the projections (14) on the wall member (11) to allow passage thereof in a first direction but prevent passage in a second, opposite direction.
