Spring Balancer is a device to suspend machines and equipment. The tension is kept stable on even if the cable is pulled out or retrived because of the tapered drum. So spring balancers can hold the tools suspended in hollow and work for flexible positioning of the tools.Air balancers use compressed air to power the lift while spring balancers use an internal spring to lift (or balance) the load. Watch this video to see a balancer in action with a heavy drill. Generally, air balancers are for heavier lifting requirements than a spring balancer and need an air system in place.