1. Material: This heavy duty automatic door closer is made of solid aluminum alloy material, commercial grade and fireproof, with high strength and hardness, anti-rust, oxidation and heat resistant, not easy to bend, deform or get damaged, and can serve a long and stable life. 2. Performance: This fire rated overhead door closer has been tested for over 1,000,000 cycles of opening and closing, with super flexible rotation and not easy to get stuck. Its extra stable structure enables it to bear a weight up to 65Kg, and it is suitable for door widths of 600-1200mm, ideal for single or double doors, wooden or glass doors. 3. Adjustable Speed: The two valves of this hydraulic buffer original positioning spring closing device are independent, allowing you to control both the movement speed of the hydraulic buffer and the oscillation and closing speed of the latch. You can self-tune the mechanism according to your needs and choose the return speed based on the environment it is placed in to avoid damaging the door or hurting people. 4. Installation and Application: It is quite easy to install this universal door closer. All necessary accessories for installation will be provided, and it can be widely used in home or commercial settings, suitable for wooden doors, glass doors, sectional doors, fire doors or metal doors. 5. Guarantee: Our products are designed to meet your needs. If you encounter any problems, you can contact us and we will be happy to solve them for you at any time.