An electromagnetic coupling device. The coupling device has a device body and at least one tongue member protruding from the device body. The tongue member has one or more ferro-magnetic engagement means provided thereon. At least one tongue member receiving means is provided on or defined by the device body and at least one electromagnet is provided substantially adjacent the receiving means. The engagement means provided on the tongue member of a second electromagnetic coupling device may be accommodated within the receiving means of the device body. The electromagnet is operable to cause the engagement means of the tongue member of the said second electromagnetic coupling device to substantially resist or prevent movement of the said tongue member within the receiving means.
