If carts proposed have replaceable wear pads the extend below the bottom of the carts to protect the bottom, the pads must be assembled with fasteners that do not protrude through the interior of the cart.

• 如果有可替代的衬垫来加厚筒的底部以保护筒底，那么这些衬垫必须附带一些加固扣牢的但是又不会太突出的扣子钩子之类的东西。