Platform lift trucks have a stable, flat platform that supports smaller loads, bulk goods, or irregularly shaped items that are not stored on pallets or skids, and they have a lifting mechanism that raises the loaded platform. Also called platform stackers, these wheeled vehicles move and lift loads to stack them or put them onto storage racks or other high surfaces in warehouses, manufacturing plants, and other industrial areas. Platform lifts need less maintenance and can maneuver more easily in tight spaces than forklifts, and they don't require certification to operate. Manual platform lifts require less maintenance than powered platform lifts. Fully or partially powered platform lifts take less physical effort to operate than manual platform lifts. Unless noted otherwise, platform lifts are for use on firm, level surfaces because they may roll back if used on inclines.