I needed a small topbox for my Supercub that fitted the only support bars that are available for it - made by Givi. The box came complete with the support plate and cover to actually make the rack and it locks on and off easily with a key. When fitted the box rattled alarmingly in use which I solved by sticking some 8mm rubber underneath. The plastic box is, however, quite flimsy and still makes a noise when on country lanes. I am going to try and put some insulation round the lid to try and help. The box does reflect the price though so I’m not too disappointed.