Robust construction and material Made from cold-rolled steel for exceptional strength and long-lasting durability. Safe 90-degree positioning Features a 90-degree positioning principle where invisible steel balls snap into place to hold the door securely after it passes 90 degrees. Adjustable positioning beads enhance stability. Easy maintenance and durability Comes with a removable core and reinforced shaft for easy disassembly and extended service life. Multifunctional design Combines door backcheck, door closer, and door suction functions for versatile applications. Applications and scenarios - Residential interior doors: control door movement, reduce noise, and prevent slamming. - Offices and commercial spaces: convenient hold-open behavior and reliable automatic closing after traversal. - Public entrances or service areas: versatile functionality to suit multiple door types and usage scenarios.