An electric stacker is sometimes called a walkie stacker

An electric stacker power propelled device that has a mast and forks that high lifting stacker loads and place them on shelves or rack beams.  It is stabilized by its outrigger legs and these must be considered when planning the rack and shelf layout.  Electric units are clean and efficient and prove to be the choice when working indoors.  Fully powered electric stacker transports loads throughout warehouse facilities quickly with less effort. Ergonomic handle feature easy-to-operate throttle with infinite adjustment of forward and reverse speeds. The emergency reverse belly switch instantly reverses direction and moves the unit forward until the swtich is released. Walkie stackers are good stewards of space and will operate in a very narrow aisle thereby adding to their value.