An attachment 100 that is suitable for being mounted to a Y- or T-shaped fence post 110 of the type that comprises a stalk and wings that project from the stalk 112. The attachment comprises a mounting portion 116 configured for mounting to the stalk 112 of the post 110, and not to the wings of the post 110, by at least one fastening element that extends through the stalk 112, the mounting portion 116 being configured such that it is restricted from rotating about the at least one fastener. The attachment 100 also comprises an elongate extension arm 118 extending from the mounting portion 116 so as to lie in or be parallel to a plane of the mounting portion 116, the elongate arm being integral wit the mounting portion. In this way, the attachment can assist in the transfer of forces from the elongate extension arm 118 into the stalk 112 of the post 110 where it can best be accommodated.
