The Gravely ZT brings commercial features and construction to a residential compact design. This is a comfortable, durable zero-turn mower that gives you the maneuverability you need to finish the job quickly without sacrificing a beautifully cut lawn. The Gravely ZT brings commercial features and construction to a residential compact design. This is a comfortable, durable zero-turn mower that gives you the maneuverability you need to finish the job quickly without sacrificing a beautifully cut lawn.