STRONG LOAD & SILENT - Each pair of invisible door hinges supports up to 265 pounds and offers a 180-degree opening angle, balancing functionality with user comfort. Built-in spacers reduce friction, enabling quiet door opening and closing to avoid disturbing EASY INSTALLATION WITH INSTRUCTION - Our hindden door hinge features a detailed positioning template in the manual for quick and accurate setup. Achieve professional, aligned results effortlessly, perfect for DIY beginners and pros alike. 3D ADJUSTABLE - No need to remove the door for three-dimensional adjustability: vertical ±3.0mm, horizontal ±3.0mm, and depth ±2.0mm. These secret door hinges are designed to fit both left-handed and right-handed doors RUST-RESISTANT - Crafted from high-quality zinc and aluminum alloy, the hidden door hardware boasts excellent rust resistance. No special maintenance or lubrication is required VERSATILE COMPATIBILITY - Our hidden hinges for doors are engineered for universal use on left-handed and right-handed doors, plus compatibility with wood, metal, and commercial doors (thickness >35mm, width <1000mm); These concealed door hinges are ideal for creating secret doors, bookshelf doors, french doors, folding doors, feature walls, and DIY projects