A Stier push-pull trolley is a type of trolley used for moving heavy loads along an overhead rail system. It is designed to be attached to the load and moved along the rail system by pulling or pushing the trolley. The Stier push-pull trolley typically has two wheels that run along the rail, with a hook or clamp that attaches to the load. The trolley can be manually pushed or pulled to move the load along the rail. Some models may also have a brake system for added safety. Push-pull trolleys are commonly used in industrial settings, such as factories or warehouses, where heavy loads need to be moved efficiently and safely. They are often used in conjunction with a hoist or crane to lift and move the load. The Stier brand is known for its high-quality and durable trolleys, which are designed to withstand heavy use and provide reliable performance over time.