A clamp (1d) comprises a clamp bracket (3f) and an elastic cord (5) threaded through a pair of apertures (7b, 9b) in the clamp bracket (3f). The clamp bracket (3f) further comprises a pair of keyhole-shaped holes (19f) for receiving an end portion (31) of the cord (5). The shape of the keyhole-shaped holes (19f) is such that the cord (5) is insertable into part of the hole (19f) when the cord is tensioned and the cord (5) is gripped by inner walls of an adjoining part of the hole (19f) when the cord is untensioned.
