If you're in the US you can use Todson (Topeak's distributor) - www.todson.com/products/ninja-master-toolbox-t16-tnja-t16?_pos=5&_sid=28c530ffd&_ss=r. Otherwise you can buy directly from Topeak website - www.topeak.com/us/en/products/329-/1383-NINJA-MASTER+-TOOLBOX-T16.