Pallet Flow provides superior density over all other systems and offers superior FIFO capabilities. The product is loaded at one end of the system, then flows to the other end to be unloaded. It also offers better product selectivity than either Drive-In or Push-Back. However, as with others, this system works best with a very limited number of SKUs. Moreover, it is the most expensive rack system by far. Potential lost pallet positions again come into play because the system is not level, due to the height and pitch of the flow rails that are inherent to the system.