The LCN 4110 door closer has a double lever, left-handed parallel arm made of forged steel, a delayed action cylinder, an aluminum powder coated finish, and is for use in heavy duty applications on interior or exterior doors. The hydraulic cylinder is made of cast iron, has a forged steel piston and double heat treated steel pinion for resistance to wear, and is certified for 10 million cycles. All-weather hydraulic fluid helps reduce the need for seasonal adjustment. The double lever arm must be installed for a low-profile, parallel arm mount. The arm is made of forged steel for high traffic settings. The cylinder has a delayed action function that holds the door open, adjustable up to 60 seconds, for additional time to pass through before closing. The door closer is left-handed, for installation on doors with hinges on the left side, and includes a plastic cover. The spring force required to open the door is adjustable from sizes 1 to 6 for interior doors up to 60" wide, or exterior doors up to 48" wide, to help comply with the Americans with Disabilities Act (ADA) when properly installed. The aluminum powder coat finish helps provide resistance to corrosion. The door closer meets American National Standards Institute (ANSI)/Builders Hardware Manufacturers Association (BHMA) A156.4 grade 1 standards for commercial buildings. It is also Underwriters Laboratories (UL) listed for a 3-hour fire rating, and complies with the UL 10C positive pressure fire test.SpecificationsCylinderCast iron with forged steel piston and double heat treated steel pinionArm constructionForged steel main arm and forearmCoverPlasticMountingParallel armInterior door width24" to 60"Exterior door width24" to 48"Maximum door opening180 degreesANSI/BHMA gradeGrade 1Cycles10 millionUL compliance3-hour fire rating, UL 10CCommercial grade door closers mechanically return a door to closure for security, conservation of heating and cooling, and fire safety. A hydraulic cylinder attached to an arm regulates the speed of closure with separate adjustments for the door's sweep and latch (the final 10 degrees) phases of movement, and backcheck for opening resistance to protect walls and guard against wind gusts. Single lever (also called track) arms maintain a low profile when installed on either side of a door, while double lever arms provide greater mechanical efficiency. In either a regular mount (on the hinge, or pull, side of the door) or a top jamb mount (on the reverse, or push side), the double lever arm projects perpendicular to the door. A parallel arm mount must be installed on the push side, for the double lever arm to occupy the recess of the door frame when at rest for a low profile. LCN manufactures door closers and other door hardware products. The company, founded in 1926, is headquartered in Princeton, IL.What's in the Box?4110 series delayed action hydraulic cylinderForged steel double lever armPlastic cylinder coverPeel-n-stick installation templateFastener pack: screw spacer, self-reaming and tapping screws