The Massey Ferguson ZT 1644 is a zero-turn mower built by Simplicity and distributed by Massey Ferguson. Produced from 1999 to 2003, it features a 16HP Kohler 1-cylinder gasoline engine, hydrostatic transmission with infinite forward and reverse speeds, and a 44" mid-mount mower deck. It is built in Port Washington, Wisconsin, USA, and offers two-wheel drive with hydrostatic differential steering and an open operator station.