Design: Built-in spring self-locking structure with fixed 90-degree positioning. It automatically locks when unfolded horizontally to deliver stable heavy load support for sofa bed frames, cabinet flip panels and storage brackets, eliminating shaking and collapsing during daily use; press the release switch to fold flat for space saving when not needed. Lightweight: Thickened integrated stamped metal construction provides outstanding load-bearing performance with slim volume, will not bend or deform under the weight of sofa mattresses, bed boards and cabinet panels. Easy Installation: Uniform pre-drilled mounting holes match standard wood screws, enabling fast DIY assembly on wooden sofa frames, bed bases and storage cabinets without extra cutting or grooving processing. Material: High-strength carbon steel with full anti-rust surface coating; built-in wear-resistant elastic spring maintains consistent self-locking elasticity after thousands of folding cycles, resistant to fatigue loosening and fracture. Versatile Application: Special heavy-duty folding support hardware for multi-functional furniture, widely applicable to sofa bed conversion frames, flip storage cabinets, hidden wall beds, multi-purpose storage furniture and all space-saving household woodworking renovation projects., Manufacturer: xhy0213