Abstract: An edge mould (36) in the form of an aluminium extrusion, has a male portion (104) and a female portion (106), the latter being defined by at least legs (105, 109). The mould, when attached to a panel edge, enables the panel to be reversible, the male and female portions of abutting moulds mating to locate the two moulds and panels and to provide a sound and drought seal at the join between two panels. The male portion (104) may have a seal (132) in a channel (108) to assist in sealing abutting moulds. Panels using such edge moulds may be used in operable wall systems and in shopfitting systems.