Features: Engineered for DR300/500/600/800 roller doors, this relays circuit board delivers precise motor control with overload protection and advanced heat dissipation for seamless automation. Builts with materials and relays technology, it supports multiple operation modes, simplified installation, and stable performances under high load industrial conditions. Suitable for property management firms, industrial warehouses, technicians, and enthusiasts upgrading garage or commercial door systems. Enhances security in residential garages, commercial entrances, and industrial zones requiring reliable automated access control. Multi interfaces design ensures compatibility with home systems, while front wiring simplifies integration into existing setups for long term durability. Specifications: Material: Plastic Applicable Model: For DR300/DR500/DR600/DR800 Size: Approx. 3.35x2.95inch(8.5x7.5cm) Package Includes: 1x Circuit Board note: Please allow 1-2cm errors due to manual measurement. Due to the differences between different monitors, the picture may not reflect the actual color from the item.