A cap for use on a palletized load has a main moulding providing housings at a pair or two pairs of opposite sides for a cassette in which a strap passes through a slotted crossbar between a drum and a hook having two prongs for engaging the underside of the platform of a pallet (e.g. at each side of a middle spacer), the strap then being tensioned by a linkage between the slotted crossbar and a lever within a slot for swinging between an inoperative position and an operative position (e.g. up to 90.degree. thereto) to rotate the crossbar to wind the strap thereon.