Motorized hoppers are used in both truck bed spreaders and tailgate spreaders. They can overhang the back of trucks and evenly spread salt. The top loading covers allow for quick filling of the hopper and keep moisture out. They differ in their storage capacities. A truck bed spreader is equipped with an enormous storage tub which sits on the bed of the truck. The spreaders can distribute large quantities of salt, without the need for refilling. The salt load directly into the tailgate spreader, which has a lower storage capacity. With capacities of 3-8 cubic feet they are suitable for many uses. They are also low-profile, so they don't block drivers' rearview.