The 4820 Auto Equalizer is LCN's pneumatically powered multi-door solution. This low-energy automatic operator provides easy access for people with disabilities, or the elderly. Designed primarily for manual opening applications that occasionally require automatic opening. LCN Pneumatic Auto Equalizer systems use the power of pressurized air to do the work of automatically opening the door. A basic pneumatic system consists of an automatic operator to provide the door control, a control box that contains the valves and electrical timing circuits, actuators to start the system, and a compressed air source. Closer cylinder constructed of high strength cast iron, full complement bearing, 1-1/2" diameter piston, and 3/4" diameter double heat treated pinion journal.