Excellent Material: The automatic spring clasp is made of stainless steel and zinc alloy. It adopts one-piece molding process and multi-channel assembly process to make the whole product durable, rust-free and long lifespan. Package Contents: After purchasing, you will get a door closer, 4 screws, an Allen key and a seal for the protective door. The stainless steel spring door closer is easy to install, no need to buy other parts. Adjustable Design: The adjustment force increases: adjust clockwise one by one, the product default force is 2 gears, and can only increase 2 gears; adjustment force decreases: simply insert the L-shaped key in the long end and press hard to restore the minimum force. Noise Reduction: The door closer can reduce the noise interference generated when closing the door, close the door slowly to reduce the damage to the door caused by strong impact, and prevent you from forgetting to close the door door. Widely Used: Our door closers for interior door are suitable for metal doors, fire doors, wooden doors, civil doors and commercial doors, almost all doors under 30 kg. The adjustable closing door automatic is an ideal choice for home, office and hotel room doors.