Automatic, the air motor stalls out upon reaching torque and exits from the nut. Tool life more than 2 million nuts (Consumable parts such as mandrels and nose-piece assembly need to be replaced regularly).   

Made of high quality hardware and carbon steel hardware, it is sturdy, durable and wear-resistant. With two independent valves, you can adjust closing and locking speed speed easily. It is easily installed by installation instructions. This Hydraulic door closer works with various types of doors: right and left opened doors, residential door, Commercial Door, wooden door, metal door, fire door, passage door, glass door with frame, hotel door, home and office doors, exterior and interior doors. DO NOT rotate the axis of door closer to 180° before installation, otherwise it will be damaged or...