top bosThere's no easier way of carrying kit on a motorcycle than a top box, which mounts to a rack at the back of the bike. Most of the top boxes in our range also let you lock your valuables away.Metal Mule Max top box. Quick info: from £499.95 for top box only, polyurethane-d mounting brackets. Just like the Max panniers, the top box is made from hh grade aluminium and aircraft grade stainless steel rivets