The Massey Ferguson ZT 1638 is a zero-turn mower built by Simplicity and distributed by Massey Ferguson during 2002-2003. It features a 16 hp Kohler Command 1-cylinder air-cooled gasoline engine, hydrostatic transmission with infinite forward and reverse speeds, and two-wheel drive with hydrostatic differential steering. The mower has an open operator station and is equipped with a 38-inch mid-mount mower deck. It was built in Port Washington, Wisconsin, USA.