The economical way to buy american pro ball bearing quality toolboxes has all the features of the professional chests except that the castors are 100mm features locks on both the topchest and rollcab and lockable steel bars that keep drawers shut ball bearing drawer runners provide superior performance and carry heavier loads both units have built in storage for locking bars when toolboxes are being used supplied with two keys for each lock overall sizes w x d x h topchest 600 x 260