A bottle jack is a type of hydraulic jack used to lift heavy loads such as vehicles or machinery. It is called a bottle jack because it has a cylindrical shape similar to a bottle. Bottle jacks are commonly used in automotive and industrial settings, and they can be found in a variety of sizes and weight capacities.Bottle jacks work by using hydraulic pressure to lift the load. The jack consists of a vertical cylinder with a piston inside that is operated by a pump handle. The pump handle is used to push hydraulic fluid into the cylinder, which causes the piston to lift the load.